Delivery-Date: Sat, 02 Nov 1996 01:54:44 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id BAA02672 for X-agentx; Sat, 2 Nov 1996 01:54:44 -0800 (PST) Received: from fsnt.future.futsoft.com ([38.242.192.5]) by fv.com (8.7.4/8.7.3) with SMTP id BAA02669 for ; Sat, 2 Nov 1996 01:54:40 -0800 (PST) Received: from kailash.future.futsoft.com (38.242.192.4) by fsnt.future.futsoft.com (Integralis SMTPRS 1.4) with SMTP id ; Sat, 02 Nov 1996 15:27:45 +0530 Received: from msgate.future.futsoft.com (msgate.future.futsoft.com [10.0.8.4]) by kailash.future.futsoft.com (8.7.1/8.7.1) with SMTP id DAA24870 for ; Sat, 2 Nov 1996 03:09:07 -0500 Note: Future Software Confidential Mail Received: by msgate.future.futsoft.com with Microsoft Mail id <327BD777@msgate.future.futsoft.com>; Sat, 02 Nov 96 15:21:27 PST From: ravendrag To: "'smtp:agentx@fv.com'" Subject: About AgentX... Date: Sat, 02 Nov 96 15:20:00 PST Message-Id: <327BD777@msgate.future.futsoft.com> Encoding: 11 TEXT X-Mailer: Microsoft Mail V3.0 Hi I am intrested in knowing about the relationship between DPI and AgentX. Also will somebody help me know the status of proposed draft for AgentX? thanx in advance regards ravendrag@future.futsoft.com   Delivery-Date: Sat, 02 Nov 1996 13:33:19 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id NAA29335 for X-agentx; Sat, 2 Nov 1996 13:33:18 -0800 (PST) Received: from relay1.smtp.psi.net (relay1.smtp.psi.net [38.8.14.2]) by fv.com (8.7.4/8.7.3) with SMTP id NAA29332 for ; Sat, 2 Nov 1996 13:33:17 -0800 (PST) Received: from nips.acec.com by relay1.smtp.psi.net (8.6.12/SMI-5.4-PSI) id QAA09087; Sat, 2 Nov 1996 16:33:14 -0500 Received: from natale by nips.acec.com (5.65/3.2.083191-American Computer and Electronics Corp. ) id AA04938; Sat, 2 Nov 1996 16:33:27 -0500 Date: Sat, 2 Nov 1996 16:32:16 EST From: Bob Natale Subject: Re: About AgentX... To: ravendrag Cc: agentx@fv.com Message-Id: Priority: Normal Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII > From: ravendrag > Date: Sat, 02 Nov 96 15:20:00 PST Hi, > I am intrested in knowing about the relationship between > DPI and AgentX. The WG decided to use the DPI v2 spec as a kind of starting point for AgentX. In the end, AgentX will incorporate features from DPI, SMUX, SNMP proxy experience, and several of the major proprietary exetensible agent products. The hope is that AgentX will facilitate the adoption of extensible agent technology in general, result in the development and deployment of many new subagents for managed components, and that those who currently build proprietary extensible agent platform products...including master agents, APIs, toolkits, and such...will be able to quickly integrate AgentX into those products. > Also will somebody help me know the status of proposed draft > for AgentX? The authors (Mike Daniele w/DEC and Bert Wijnen w/IBM) and the editor (Dale Francisco w/Cisco-Stratacom)--with helpful contributions from a number of other WG participants--have been VERY busily at work on Rev 5 of the draft protocol spec over the past month or so. It is anticipated that this will be posted to the list in the coming week. We will then try to focus the disucssion toward any editorial errors, technical show-stoppers, and implementation/interoperability factors that might need attention. We will also assess the level of WG consensus during that time. Any changes resulting from that round of discussion will be incorporated into the "official" WG draft protocol document which will be submitted to the IETF Secretariat before the 11/26 cut-off date for the Dec (San Jose) IETF. The WG will hold one meeting in San Jose (Wed 9/11 @9:00am) and the major agenda item(s) will center on implementation and interoperability plans/experience and reports. Feel free (anyone) to let me know if you have any questions, problems, or suggestions wrt any of the above. And please keep a watch on the list for the new draft and read it and comment, if necessary, in a timely manner. Thanks. Cordially, BobN ------ ISO 9000 Registered, Hardware and Software Divsions ----- Bob Natale | ACE*COMM | 301-258-9850 [v] Dir, Net Mgmt Prod | 209 Perry Pkwy | 301-921-0434 [f] natale@acec.com | Gaithersburg MD 20877 | http://www.acec.com ---------- WinSNMP DLL, SDK, and Apps for Win16/Win32 ---------- ------- NetPlus (r) "FCAPS" Telemanagement Applications --------   Delivery-Date: Tue, 05 Nov 1996 09:15:25 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id JAA04767 for X-agentx; Tue, 5 Nov 1996 09:15:25 -0800 (PST) Received: from stratacom.strata.com (stratacom.strata.com [204.179.0.2]) by fv.com (8.7.4/8.7.3) with SMTP id JAA04764 for ; Tue, 5 Nov 1996 09:15:24 -0800 (PST) Received: from Strata.COM (kiwi.strata.com) by stratacom.strata.com (4.1/SMI-4.1/Gatekeeper.Strata.Com-950201) id AA17249; Tue, 5 Nov 96 09:15:19 PST Received: from santa.strata.com (santa-le1) by Strata.COM (4.1/SMI-4.1/StrataCom-GCA-Kiwi-931007-1) id AA25908; Tue, 5 Nov 96 09:14:24 PST Received: from marvell.strata.com by santa.strata.com (4.1/SMI-4.1/StrataCom-GCA-SunClient-LOCAL-931101) id AA21042; Tue, 5 Nov 96 09:15:18 PST Date: Tue, 5 Nov 96 09:15:18 PST From: dfrancis@stratacom.com (Dale Francisco) Message-Id: <9611051715.AA21042@santa.strata.com> To: agentx@fv.com Subject: ver 00.05 of AgentX protocol draft to be posted I'm sending in a single following post revision 00.05 of the proposed AgentX Protocol internet draft. There are numerous changes, both substantive and stylistic, from the previous version. Please see section 11 of the draft for a summary of open issues and new features. Please direct questions, comments, and suggested changes to the list (agentx@fv.com). Thanks, Dale Francisco Editor, AgentX WG dfrancis@cisco.com voice: (805) 961-3642 fax: (805) 961-3600   Delivery-Date: Tue, 05 Nov 1996 09:19:14 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id JAA05141 for X-agentx; Tue, 5 Nov 1996 09:19:13 -0800 (PST) Received: from stratacom.strata.com (stratacom.strata.com [204.179.0.2]) by fv.com (8.7.4/8.7.3) with SMTP id JAA05138 for ; Tue, 5 Nov 1996 09:19:12 -0800 (PST) Received: from Strata.COM (kiwi.strata.com) by stratacom.strata.com (4.1/SMI-4.1/Gatekeeper.Strata.Com-950201) id AA17291; Tue, 5 Nov 96 09:19:07 PST Received: from santa.strata.com (santa-le1) by Strata.COM (4.1/SMI-4.1/StrataCom-GCA-Kiwi-931007-1) id AA26353; Tue, 5 Nov 96 09:18:06 PST Received: from marvell.strata.com by santa.strata.com (4.1/SMI-4.1/StrataCom-GCA-SunClient-LOCAL-931101) id AA21123; Tue, 5 Nov 96 09:18:56 PST Date: Tue, 5 Nov 96 09:18:56 PST From: dfrancis@stratacom.com (Dale Francisco) Message-Id: <9611051718.AA21123@santa.strata.com> To: agentx@fv.com Subject: AgentX protocol draft, ver 00.05 Agent Extensibility (AgentX) Protocol Version 1 Mike Daniele Digital Equipment Corporation daniele@zk3.dec.com Bert Wijnen T.J. Watson Research Center, IBM Corp. wijnen@vnet.ibm.com Dale Francisco (editor) Cisco Systems, Inc. dfrancis@cisco.com Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Daniele/Wijnen Expires May 1997 [Page 1] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 Table of Contents 1 Introduction......................................................5 2 The SNMP Framework................................................5 2.1 A Note on Terminology.........................................5 3 Extending the MIB.................................................6 3.1 Motivation for AgentX.........................................6 4 AgentX Framework..................................................7 4.1 AgentX Roles..................................................7 4.2 Design Goals for AgentX.......................................8 5 AgentX Encodings..................................................9 5.1 Object Identifier............................................10 5.2 SearchRange..................................................12 5.3 Octet String.................................................13 5.4 Value Representation.........................................14 6 Protocol Definitions.............................................16 6.1 AgentX PDU Header............................................16 6.1.1 Context..................................................17 6.2 AgentX PDUs..................................................18 6.2.1 The agentx-Open-PDU......................................18 6.2.1.1 agentx-Open-PDU Fields...............................18 6.2.2 The agentx-Close-PDU.....................................19 6.2.2.1 agentx-Close-PDU Fields..............................20 6.2.3 The agentx-Register-PDU..................................21 6.2.3.1 agentx-Register-PDU Fields...........................22 6.2.4 The agentx-Unregister-PDU................................24 6.2.4.1 agentx-Unregister-PDU Fields.........................25 6.2.5 The agentx-Get-PDU.......................................26 6.2.5.1 agentx-Get-PDU Fields................................27 6.2.6 The agentx-GetNext-PDU...................................28 6.2.7 The agentx-GetBulk-PDU...................................29 6.2.8 The agentx-TestSet-PDU...................................30 6.2.8.1 agentx-TestSet-PDU Fields............................31 6.2.9 The agentx-CommitSet, -UndoSet, -CleanupSet, and -Ping PDUs...........................................31 6.2.10 The agentx-Notify-PDU...................................31 6.2.10.1 agentx-Notify-PDU Fields............................32 6.2.11 The agentx-IndexReserve-PDU.............................32 6.2.11.1 agentx-IndexReserve-PDU fields......................32 6.2.12 The agentx-IndexUnreserve-PDU...........................33 6.2.12.1 agentx-IndexUnreserve-PDU fields....................33 6.2.13 The agentx-AddAgentCaps-PDU.............................34 6.2.13.1 agentx-AddAgentCaps-PDU Fields......................35 6.2.14 The agentx-RemoveAgentCaps-PDU..........................36 6.2.14.1 agentx-RemoveAgentCaps-PDU Fields...................36 6.2.15 The agentx-Response-PDU.................................37 Daniele/Wijnen Expires May 1997 [Page 2] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.15.1 agentx-Response-PDU Fields..........................37 7 Elements of Procedure............................................38 7.1 Processing AgentX Administrative Messages....................38 7.1.1 Processing the agentx-Open-PDU...........................38 7.1.2 Processing the agentx-IndexReserve-PDU...................39 7.1.3 Processing the agentx-IndexUnreserve-PDU.................41 7.1.4 Processing the agentx-Register-PDU.......................42 7.1.4.1 Handling Duplicate OID Ranges........................44 7.1.5 Processing the agentx-Unregister-PDU.....................44 7.1.6 Processing the agentx-AddAgentCaps-PDU...................45 7.1.7 Processing the agentx-RemoveAgentCaps-PDU................45 7.1.8 Processing the agentx-Close-PDU..........................45 7.1.9 Detecting Connection Loss................................46 7.1.10 Processing the agentx-Notify-PDU........................46 7.1.11 Processing the agentx-Ping-PDU..........................47 7.2 Processing Received SNMP Protocol Messages...................47 7.2.1 Dispatching AgentX PDUs..................................47 7.2.1.1 agentx-Get-PDU.......................................48 7.2.1.2 agentx-GetNext-PDU...................................49 7.2.1.3 agentx-GetBulk-PDU...................................50 7.2.1.4 agentx-TestSet-PDU...................................51 7.2.1.5 Dispatch.............................................52 7.2.2 Subagent Processing of agentx-Get, GetNext, GetBulk-PDUs.............................................52 7.2.2.1 Subagent Processing of the agentx-Get-PDU............53 7.2.2.2 Subagent Processing of the agentx-GetNext-PDU...................................53 7.2.2.3 Subagent Processing of the agentx-GetBulk-PDU...................................54 7.2.3 Subagent Processing of agentx-TestSet, -CommitSet, -UndoSet, -CleanupSet-PDUs...................55 7.2.3.1 Subagent Processing of the agentx-TestSet-PDU...................................55 7.2.3.2 Subagent Processing of the agentx-CommitSet-PDU.................................56 7.2.3.3 Subagent Processing of the agentx-UndoSet-PDU...................................56 7.2.3.4 Subagent Processing of the agentx-CleanupSet-PDU................................57 7.2.4 Master Agent Processing of AgentX Responses..............57 7.2.4.1 Common Processing of All AgentX Response PDUs.................................................57 7.2.4.2 Processing of Responses to agentx-Get-PDUs...........57 7.2.4.3 Processing of Responses to agentx-GetNext- and agentx-GetBulk-PDUs..............58 7.2.4.4 Processing of Responses to agentx-TestSet-PDUs..................................59 7.2.4.5 Processing of Responses to agentx-CommitSet-PDUs................................60 Daniele/Wijnen Expires May 1997 [Page 3] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 7.2.4.6 Processing of Responses to agentx-UndoSet-PDUs..................................60 7.2.5 Sending the SNMP Response-PDU............................60 7.2.6 MIB Views................................................61 8 Transport Mappings...............................................61 8.1 AgentX over TCP..............................................61 8.1.1 Well-known Values........................................61 8.1.2 Operation................................................61 8.2 AgentX over UNIX-domain Sockets..............................62 8.2.1 Well-known Values........................................62 8.2.2 Operation................................................62 9 Security Considerations..........................................62 10 Acknowledgements................................................62 11 Questions and Issues............................................63 11.1 Design......................................................63 11.2 Miscellaneous Issues/Decisions..............................63 11.3 New in this version.........................................65 12 Authors' and Editor's Addresses.................................66 13 References......................................................66 Daniele/Wijnen Expires May 1997 [Page 4] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 1. Introduction This memo defines a framework for extensible SNMP agents. It defines processing entities called master agents and subagents, a protocol (AgentX) used to communicate between them, and the elements of procedure by which the extensible agent processes SNMP protocol messages. 2. The SNMP Framework A management system contains: several (potentially many) nodes, each with a processing entity, termed an agent, which has access to management instrumentation; at least one management station; and, a management protocol, used to convey management information between the agents and management stations. Operations of the protocol are carried out under an administrative framework which defines authentication, authorization, access control, and privacy policies. Management stations execute management applications which monitor and control managed elements. Managed elements are devices such as hosts, routers, terminal servers, etc., which are monitored and controlled via access to their management information. Management information is viewed as a collection of managed objects, residing in a virtual information store, termed the Management Information Base (MIB). Collections of related objects are defined in MIB modules. These modules are written using a subset of OSI's Abstract Syntax Notation One (ASN.1) [1], termed the Structure of Management Information (SMI) (see RFC 1902 [2]). 2.1. A Note on Terminology The term "variable" refers to an instance of a non-aggregate object type defined according to the conventions set forth in the SMI (RFC 1902, [2]) or the textual conventions based on the SMI (RFC 1903 [3]). The term "variable binding" normally refers to the pairing of the name of a variable and its associated value. However, if certain kinds of exceptional conditions occur during processing of a retrieval request, a variable binding will pair a name and an indication of that exception. A variable-binding list is a simple list of variable bindings. The name of a variable is an OBJECT IDENTIFIER, which is the concatenation of the OBJECT IDENTIFIER of the corresponding object type together with an OBJECT IDENTIFIER fragment identifying the instance. The OBJECT IDENTIFIER of the corresponding object-type is called the OBJECT IDENTIFIER prefix of the variable. For the purpose of exposition, the original Internet-standard Daniele/Wijnen Expires May 1997 [Page 5] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 Network Management Framework, as described in RFCs 1155 (STD 16), 1157 (STD 15), and 1212 (STD 16), is termed the SNMP version 1 framework (SNMPv1). The current framework, as described in RFCs 1902-1908, is termed the SNMP version 2 framework (SNMPv2). 3. Extending the MIB New MIB modules that extend the Internet-standard MIB are continuously being defined by various IETF working groups. It is also common for enterprises or individuals to create or extend enterprise-specific or experimental MIBs. As a result, managed devices are frequently complex collections of manageable components that have been independently installed on a managed node. Each component provides instrumentation for the managed objects defined in the MIB module(s) it implements. Neither the SNMP version 1 or version 2 framework addresses how managed objects may be dynamically added to or removed from the agent view within a particular managed node. 3.1. Motivation for AgentX This very real need to dynamically extend the management objects within a node has given rise to a variety of "extensible agents", which typically comprise - a "master" agent that is available on the standard transport address and that accepts SNMP protocol messages - a set of "subagents" that each contain management instrumentation - a protocol that operates between the master agent and subagents, permitting subagents to "connect" to the master agent, and the master agent to multiplex received SNMP protocol messages amongst the subagents. - a set of tools to aid subagent development, and a runtime (API) environment that hides much of the protocol operation between a subagent and the master agent. The wide deployment of extensible SNMP agents, coupled with the lack of Internet standards in this area, makes it difficult to field SNMP-manageable applications. A vendor may have to support several different subagent environments (APIs) in order to support different target platforms. It can also become quite cumbersome to configure subagents and (possibly multiple) master agents on a particular managed node. Daniele/Wijnen Expires May 1997 [Page 6] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 Specifying a standard protocol for agent extensibility (AgentX) provides the technical foundation required to solve both of these problems. Independently developed AgentX-capable master agents and subagents will be able to interoperate at the protocol level. Vendors can continue to differentiate their products in all other respects. 4. AgentX Framework Within the SNMP framework, a managed node contains a processing entity, called an agent, which has access to management information. Within the AgentX framework, an agent is further defined to consist of - a single processing entity called the master agent, which sends and receives SNMP protocol messages in an agent role (as specified by the SNMP version 1 and version 2 framework documents) but typically has little or no direct access to management information. - 0 or more processing entities called subagents, which are "shielded" from the SNMP protocol messages processed by the master agent, but which have access to management information. The master and subagent entities communicate via AgentX protocol messages, as specified in this memo. Other interfaces (if any) on these entities, and their associated protocols, are outside the scope of this document. While some of the AgentX protocol messages appear similar in syntax and semantics to the SNMP, bear in mind that AgentX is not SNMP. The internal operations of AgentX are invisible to an SNMP entity operating in a manager role. From a manager's point of view, an extensible agent behaves exactly as would a non-extensible (monolithic) agent that has access to the same management instrumentation. This transparency to managers is a fundamental requirement of AgentX, and is what differentiates AgentX subagents from SNMP proxy agents. 4.1. AgentX Roles An entity acting in a master agent role performs the following functions: - Accepts AgentX session establishment requests from subagents. Daniele/Wijnen Expires May 1997 [Page 7] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 - Accepts registration of MIB regions by subagents. - Sends and accepts SNMP protocol messages on the agent's specified transport addresses. - Implements the agent role Elements of Procedure specified for the administrative framework applicable to the SNMP protocol message, except where they specify performing management operations. (The application of MIB views, and the access control policy for the managed node, are implemented by the master agent.) - Provides instrumentation for the MIB objects defined in RFC 1907 [5], and for any MIB objects relevant to any administrative framework it supports. - Sends and receives AgentX protocol messages to access management information, based on the current registry of MIB regions. - Forwards notifications on behalf of subagents. An entity acting in a subagent role performs the following functions: - Initiates an AgentX session with the master agent. - Registers MIB regions with the master agent. - Instantiates managed objects. - Binds OIDs within its registered MIB regions to actual variables. - Performs management operations on variables. - Initiates notifications. 4.2. Design Goals for AgentX The primary goals of the design described in this memo are to 1) Define a standard protocol and "rules of engagement" for interoperability between management instrumentation and extensible agents. 2) Provide a mechanism for independently developed subagents to integrate into the extensible agent on a particular managed node in such a way that they need not be aware of any other existing subagents. Daniele/Wijnen Expires May 1997 [Page 8] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 As described below, support for index reservation, overlapping registration, and the open registration method ("open" in the sense that subagents are not required to know the state of pre-existing registrations in order for registration to work) provide such a mechanism. 3) Enhance performance where possible. Some of the design decisions made with this in mind include: - 32-bit alignment of data within PDUs - Native byte-order encoding by subagents - In any single request/response exchange between master agent and subagent, all variable bindings targeted for a subagent are included in a single AgentX PDU sent to that subagent. Note: In some cases multiple request/response exchanges may be required in order to process a single management request; for example, in processing some SNMP GetBulk requests. - Subagent returns a single response PDU, which contains as much data as possible; its limits (for Next/Bulk) are its own size constraints, or the upper bound on variable binding names established by the master agent. As a general architectural principle, this memo proposes that there should be a division of labor between master agent and subagent: The master agent is MIB ignorant and SNMP omniscient, while the subagent is SNMP ignorant and MIB omniscient. That is, master agents are exclusively concerned with SNMP operations and the translations to and from AgentX protocol operations needed to carry them out, subagents are exclusively concerned with management instrumentation, and neither should intrude on the other's territory. For questions and open issues, see section 11 at the end of this memo. 5. AgentX Encodings AgentX PDUs consist of a common header, followed by PDU-specific data of variable length. Unlike SNMP PDUs, AgentX PDUs are not encoded using the BER (as specified in ISO 8824 [1]), but are transmitted as a contiguous byte stream. The data within this stream is organized to provide natural alignment with respect to the start of the PDU, permitting direct (integer) access by the processing entities. The fields in the header are encoded in network byte order (most Daniele/Wijnen Expires May 1997 [Page 9] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 significant byte first). Fields within the PDUs are encoded either most significant byte first, or least significant byte first. The subagent selects which byte ordering to use when it establishes an AgentX session. PDUs are depicted in this memo using the following convention (where byte 1 is the first transmitted byte): +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | byte 1 | byte 2 | byte 3 | byte 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | byte 5 | byte 6 | byte 7 | byte 8 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... Fields marked "" are reserved for future use and must be zero-filled. 5.1. Object Identifier An object identifier is encoded as a 4-byte header, followed by a variable number of contiguous 4-byte fields representing sub-identifiers. This representation (termed Object Identifier) is as follows: Object Identifier +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | include | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Object Identifier header fields: n_subid The number (0-128) of sub-identifiers in the object identifier. An ordered list of `n_subid' 4-byte sub-identifiers follows the 4-byte header. prefix An unsigned value used to reduce the length of object identifier encodings. A non-zero value `x' is interpreted as Daniele/Wijnen Expires May 1997 [Page 10] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 the first sub-identifier after `internet' (1.3.6.1), and indicates an implicit prefix `internet.x' to the actual sub-identifiers encoded in the Object Identifier. For example, a prefix field value `2' indicates an implicit prefix `1.3.6.1.2'. A value of 0 in the prefix field indicates there is no prefix to the sub-identifiers. include Used only when the Object Identifier is the start of a SearchRange. Examples: sysDescr.0 (1.3.6.1.2.1.1.1.0) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 4 | 2 | 0 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1.2.3.4 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 4 | 0 | 0 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ A null Object Identifier consists of the 4-byte header with all bytes set to 0. Daniele/Wijnen Expires May 1997 [Page 11] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 5.2. SearchRange A SearchRange consists of two Object Identifiers. In its communication with a subagent, the master agent uses a SearchRange to identify a requested variable binding, and, in GetNext and GetBulk operations, to set an upper bound on the names of managed object instances the subagent may send in reply. The first Object Identifier in a SearchRange (called the starting OID) indicates the beginning of the range. It is frequently (but not necessarily) the name of a requested variable binding. The `include' field in this OID's header is a boolean value indicating whether or not the starting OID is included in the range. The second object identifier indicates the non-inclusive end of the range, and its `include' field is always 0. Example: To indicate a search range from 1.3.6.1.2.1.25.2 (inclusive) to 1.3.6.1.2.1.25.2.1 (exclusive), the SearchRange would be (start) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 3 | 2 | 1 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 25 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (end) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 4 | 2 | 0 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 25 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ A SearchRangeList is a contiguous list of SearchRanges. Daniele/Wijnen Expires May 1997 [Page 12] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 5.3. Octet String An octet string is represented by a contiguous series of bytes, beginning with a 4-byte integer whose value is the number of octets in the octet string, followed by the octets themselves. This representation is termed an Octet String. If the last octet does not end on a 4-byte offset from the start of the Octet String, padding bytes are appended to achieve alignment of following data. This padding must be added even if the Octet String is the last item in the PDU. Padding bytes must be zero filled. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ A null Octet String consists of a 4-byte length field set to 0. Daniele/Wijnen Expires May 1997 [Page 13] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 5.4. Value Representation Variable bindings may be encoded within the variable-length portion of some PDUs. The representation of a variable binding (termed a VarBind) consists of a 2-byte type field, a name (Object Identifier), and the actual value data. VarBind +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | v.type | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (v.name) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (v.data) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ VarBind fields: v.type Indicates the variable binding's syntax, and must be one of the following (SNMPv2 SMI) values: Integer (2), Octet String (4), Object Identifier (6), IpAddress (64), Counter32 (65), Gauge32 (66), TimeTicks (67), Opaque (68), Counter64 (70), noSuchObject (128), Daniele/Wijnen Expires May 1997 [Page 14] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 noSuchInstance (129), endOfMibView (130) v.name The Object Identifier which names the variable. v.data The actual value, encoded as follows: - Integer, Counter32, Gauge32, and TimeTicks are encoded as 4 contiguous bytes. If the subagent chose network byte ordering (see 7.1.1., Processing the agentx-Open-PDU, item 3), the bytes are ordered most significant to least significant, otherwise they are ordered least significant to most significant. - Counter64 is encoded as 8 contiguous bytes. If the subagent chose network byte ordering (see 7.1.1., Processing the agentx-Open-PDU, item 3), the bytes are ordered most significant to least significant, otherwise they are ordered least significant to most significant. - Object Identifiers are encoded as described in section 5.1, Object Identifier. - IpAddress, Opaque, and Octet String are all octet strings and are encoded as described in section 5.3, Octet String. Value data always follows v.name whenever v.type is one of the above types. These data bytes are present even if they will not be used (as, for example, in certain types of index reservation). - noSuchObject, noSuchInstance, and endOfMibView do not contain any encoded value. Value data never follows v.name in these cases. Note that the VarBind itself does not contain the value size. That information is implied for the fixed-length types, and explicitly contained in the encodings of variable-length types (Object Identifier and Octet String). A VarBindList is a contiguous list of VarBinds. Daniele/Wijnen Expires May 1997 [Page 15] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6. Protocol Definitions 6.1. AgentX PDU Header The AgentX PDU header is a fixed-format, 12-octet structure, whose data are always transmitted in network byte order: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version | h.type | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ An AgentX PDU header contains the following fields: h.version The version of the AgentX protocol (1 for this draft). h.type The PDU type; one of the following values: agentx-Open-PDU (1), agentx-Close-PDU (2), agentx-Register-PDU (3), agentx-Unregister-PDU (4), agentx-Get-PDU (5), agentx-GetNext-PDU (6), agentx-GetBulk-PDU (7), agentx-TestSet-PDU (8), agentx-CommitSet-PDU (9), agentx-UndoSet-PDU (10), agentx-CleanupSet-PDU (11), agentx-Notify-PDU (12), agentx-Ping-PDU (13), agentx-IndexReserve-PDU (14), agentx-IndexUnreserve-PDU (15), agentx-AddAgentCaps-PDU (16), agentx-RemoveAgentCaps-PDU (17), agentx-Response-PDU (18) h.payload_length The size in octets of the PDU contents, excluding the 12-byte header. As a result of the encoding schemes and PDU layouts, this value will always be either 0, or a multiple of 4. Daniele/Wijnen Expires May 1997 [Page 16] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 h.ID A packet ID that should be kept unique by the sending entity. The response to this PDU will contain the same value in its h.ID field. Master agents typically increment this value for each PDU sent, and wrap if the maximum value is reached. h.flags A bitmask, with bit 0 the leftmost bit. The bit definitions are as follows: Bit Definition --- ---------- 0 INSTANCE_REGISTRATION 1 NEW_INDEX 2 ANY_INDEX 3 NON_DEFAULT_CONTEXT 4 NETWORK_BYTE_ORDER 5-15 (reserved) 6.1.1. Context In the SNMPv1 or v2c frameworks, the community string may be used as an index into a local repository of configuration information that may include community profiles or more complex context information. Future versions of the SNMP will likely formalize this notion of "context". AgentX provides a mechanism for transmitting a context specification within relevant PDUs, but does not place any constraints on the content of that specification. An optional context field may be present in the agentx-Register-, UnRegister-, AddAgentCaps-, RemoveAgentCaps-, Get-, GetNext-, GetBulk-, and TestSet-PDUs. If the NON_DEFAULT_CONTEXT bit in the AgentX header field h.flags is clear, then there is no context field in the PDU, and the operation refers to the default context. If the NON_DEFAULT_CONTEXT bit is set, then a context field immediately follows the AgentX header, and the operation refers to that specific context. The context is represented as an Octet String. There are no constraints on its length or contents. Thus, all of these AgentX PDUs (that is, those listed immediately above) refer to, or "indicate" a context, which is either the default context, or a non-default context explicitly named in the PDU. Daniele/Wijnen Expires May 1997 [Page 17] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2. AgentX PDUs 6.2.1. The agentx-Open-PDU An agentx-Open-PDU is generated by a subagent to request establishment of an AgentX session with the master agent. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (1) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | o.timeout | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (o.id) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | subidentifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | subidentifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (o.descr) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6.2.1.1. agentx-Open-PDU Fields An agentx-Open-PDU contains the following fields: o.timeout The length of time, in seconds, that a master agent should allow to elapse after dispatching a message to a subagent Daniele/Wijnen Expires May 1997 [Page 18] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 before it regards the subagent as not responding. This is a subagent-wide default value that may be overridden by values associated with specific registered MIB regions. The default value of `0' indicates that no subagent-wide value is requested. o.id An Object Identifier that identifies the subagent. Subagents that do not support such an notion may send a null Object Identifier. o.descr An Octet String containing a DisplayString describing the subagent. 6.2.2. The agentx-Close-PDU An agentx-Close-PDU issued by either a subagent or the master agent terminates an AgentX session. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (2) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | c.reason | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Daniele/Wijnen Expires May 1997 [Page 19] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.2.1. agentx-Close-PDU Fields An agentx-Close-PDU contains the following field: c.reason An enumerated value that gives the reason that the master agent or subagent closed the AgentX session. This field may take one of the following values: reasonOther(1) None of the following reasons reasonProtocolError(2) Too many AgentX protocol errors from peer reasonTimeouts(3) Too many timeouts waiting for peer reasonShutdown(4) Sending entity is shutting down reasonByManager(5) Due to Set operation Daniele/Wijnen Expires May 1997 [Page 20] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.3. The agentx-Register-PDU An agentx-Register-PDU is generated by a subagent for each region of the MIB variable naming tree (within one or more contexts) that it wishes to support. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (3) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (r.context) (OPTIONAL) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | r.timeout | r.priority | r.range_subid | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (r.region) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (r.upper_bound) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | optional upper-bound sub-identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Daniele/Wijnen Expires May 1997 [Page 21] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.3.1. agentx-Register-PDU Fields An agentx-Register-PDU contains the following fields: r.context An optional non-default context. r.timeout The length of time, in seconds, that a master agent should allow to elapse after dispatching a message to a subagent before it regards the subagent as not responding. r.timeout applies only to messages that concern MIB objects within r.region. It overrides both the subagent-wide value (if any) indicated when the AgentX session with the master agent was established, and the master agent's default timeout. The default value for r.timeout is `0' (no override). r.priority A value between 1 and 255, used to achieve a desired configuration when different subagents register identical or overlapping regions. Subagents with no particular knowledge of priority should register with the default value of `255' (lowest priority). In the master agent's dispatching algorithm, smaller values of r.priority take precedence over larger values, as described in section 7.1.4.1. r.region An Object Identifier that, in conjunction with r.range_subid, indicates a region of the MIB that a subagent wishes to support. It may be a fully-qualified instance name, a partial instance name, a MIB table, or ranges of any of these. The choice of what to register is implementation-specific; this memo does not specify permissible values. Standard practice however is for a subagent to register at the highest level of the naming tree that makes sense. Registration of fully-qualified instances is typically done only when a subagent can perform management operations only on particular rows of a conceptual table. If r.region is in fact a fully qualified instance name, the INSTANCE_REGISTRATION bit in h.flags must be set, otherwise it must be cleared. The master agent may save this information to optimize subsequent operational dispatching. Daniele/Wijnen Expires May 1997 [Page 22] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 r.range_subid Permits specifying a range in place of one of r.region's sub-identifiers. If this value is 0, no range is specified. Otherwise the `r.range_subid'-th sub-identifier in r.region is a range lower bound, and the range upper bound sub-identifier (r.upper_bound) immediately follows r.region. This permits registering a conceptual row with a single PDU. For example, the following PDU would register row 7 of the RFC 1573 ifTable (1.3.6.1.2.1.2.2.1.1-22.7): (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (3) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | r.timeout | r.priority | 5 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (r.region) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 6 | 2 | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (r.upper_bound) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 22 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Daniele/Wijnen Expires May 1997 [Page 23] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.4. The agentx-Unregister-PDU The agentx-Unregister-PDU is sent by a subagent to remove a previously registered MIB region from the master agent's OID space. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (4) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (u.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | u.range_subid | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (u.region) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (u.upper_bound) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | optional upper-bound sub-identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Daniele/Wijnen Expires May 1997 [Page 24] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.4.1. agentx-Unregister-PDU Fields An agentx-Unregister-PDU contains the following fields: u.context An optional non-default context. u.region Indicates a previously-registered region of the MIB that a subagent no longer wishes to support. It may be a fully-qualified instance name, a partial instance name, a MIB table or group, or ranges of any of these. Daniele/Wijnen Expires May 1997 [Page 25] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.5. The agentx-Get-PDU (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (5) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.sr) (start 1) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | include | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (end 1) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... Daniele/Wijnen Expires May 1997 [Page 26] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.5.1 agentx-Get-PDU Fields An agentx-Get-PDU contains the following fields: g.context An optional non-default context. g.sr A SearchRangeList containing the requested variables for this subagent. Daniele/Wijnen Expires May 1997 [Page 27] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.6. The agentx-GetNext-PDU (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (6) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.sr) ... Daniele/Wijnen Expires May 1997 [Page 28] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.7. The agentx-GetBulk-PDU (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (7) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | g.non_repeaters | g.max_repetitions | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (g.sr) ... Daniele/Wijnen Expires May 1997 [Page 29] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.8. The agentx-TestSet-PDU (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (8) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (t.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (t.vb) (VarBind 1) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | v.type | v.size | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... (VarBind n) Daniele/Wijnen Expires May 1997 [Page 30] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.8.1. agentx-TestSet-PDU Fields An agentx-TestSet-PDU contains the following fields: t.context An optional non-default context. t.vb A VarBindList containing the requested variable bindings for this subagent. 6.2.9. The agentx-CommitSet, -UndoSet, -CleanupSet, and -Ping PDUs These PDUs consist of the AgentX header only. The agentx-CommitSet-, -UndoSet-, and -Cleanup-PDUs are used in processing an SNMP SetRequest operation. The agentx-Ping-PDU is sent by a subagent to the master agent to monitor the master agent's ability to receive and send AgentX PDUs over their shared AgentX session. 6.2.10. The agentx-Notify-PDU An agentx-Notify-PDU is sent by a subagent to cause the master agent to forward a notification. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (12) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (n.context) OPTIONAL +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Padding (as required) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (n.vb) ... Daniele/Wijnen Expires May 1997 [Page 31] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.10.1. agentx-Notify-PDU Fields An agentx-Notify-PDU contains the following fields: n.context An optional non-default context. n.vb A VarBindList whose contents define the actual PDU to be sent. This memo places the following restrictions on its contents: - If the subagent supplies sysUpTime.0, it must be present as the first varbind. - snmpTrapOID.0 must be present, as the second varbind if sysUpTime.0 was supplied, as the first if it was not. 6.2.11. The agentx-IndexReserve-PDU An agentx-IndexReserve-PDU is sent by a subagent to reserve a value for specific index objects. This feature is typically used by subagents that instantiate individual conceptual rows of a MIB table. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (14) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (i.vb) ... 6.2.11.1 agentx-IndexReserve-PDU fields An agentx-IndexReserve-PDU contains the following fields: i.vb A VarBindList containing the index names and values requested for reservation. Daniele/Wijnen Expires May 1997 [Page 32] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.12. The agentx-IndexUnreserve-PDU An agentx-IndexUnreserve-PDU is sent by a subagent to release previously reserved index values. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (15) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (i.vb) ... 6.2.12.1 agentx-IndexUnreserve-PDU fields An agentx-IndexUnreserve-PDU contains the following fields: i.vb A VarBindList containing the index names and values to be released. Daniele/Wijnen Expires May 1997 [Page 33] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.13. The agentx-AddAgentCaps-PDU An agentx-AddAgentCaps-PDU is generated by a subagent to inform the master agent of its agent capabilities. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (16) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (a.context) (OPTIONAL) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Optional Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (a.id) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (a.descr) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Optional Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Daniele/Wijnen Expires May 1997 [Page 34] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.13.1. agentx-AddAgentCaps-PDU Fields An agentx-AddAgentCaps-PDU contains the following fields: a.context An optional non-default context. a.id An Object Identifier containing the value of an invocation of the AGENT-CAPABILITIES macro, which the master agent exports as a value of sysORID for the indicated context. (Recall that the value of an invocation of an AGENT-CAPABILITIES macro is an object identifier that describes a precise level of support with respect to implemented MIB modules. A more complete discussion of the AGENT-CAPABILITIES macro and related sysORID values can be found in section 6 of RFC 1904 [10].) a.descr An Octet String containing a DisplayString to be used as the value of sysORDescr corresponding to the sysORID value above. Daniele/Wijnen Expires May 1997 [Page 35] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.14. The agentx-RemoveAgentCaps-PDU An agentx-RemoveAgentCaps-PDU is generated by a subagent to request that the master agent stop exporting a particular value of sysORID. This value must have previously been advertised by the subagent in an agentx-AddAgentCaps-PDU. (AgentX header) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (17) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (a.context) (OPTIONAL) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet String Length (L) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet 1 | Octet 2 | Octet 3 | Octet 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Octet L - 1 | Octet L | Optional Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ (a.id) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_subid | prefix | 0 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-identifier #n_subid | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6.2.14.1. agentx-RemoveAgentCaps-PDU Fields An agentx-RemoveAgentCaps-PDU contains the following fields: a.context An optional non-default context. a.id An ObjectIdentifier containing the value of sysORID that should no longer be exported. Daniele/Wijnen Expires May 1997 [Page 36] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 6.2.15. The agentx-Response-PDU +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.version (1) | h.type (18) | h.payload_length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | h.flags | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | res.error | res.index | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... (optional fields) 6.2.15.1. agentx-Response-PDU Fields An agentx-Response-PDU contains the following fields: h.ID Must be identical to the h.ID value in the PDU to which this PDU is a response. h.flags This field is ignored during response PDU processing. res.error Indicates error status (including 'noError'). Values are limited to those defined for errors in the SNMPv2 SMI (RFC 1905 [4]), and the following AgentX-specific values: alreadyOpen (256), openFailed (257), notOpen (258), indexUnsupportedType (259), indexWrongType (260), indexAlreadyReserved (261), indexNoneAvailable (262), indexNotCurrentlyReserved (263), unsupportedContext (264), duplicateRegistration (265), unknownRegistration (266), unknownAgentCaps (267) Daniele/Wijnen Expires May 1997 [Page 37] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 res.index In error cases, this is the index of the failed variable binding within a received request PDU. Other data may follow these latter two fields, depending on which AgentX PDU is being responded to. These data are specified in the subsequent elements of procedure. 7. Elements of Procedure This section describes the actions of protocol entities (master agents and subagents) implementing the AgentX protocol. Note, however, that it is not intended to constrain the internal architecture of any conformant implementation. The actions of AgentX protocol entities can be broadly categorized under two headings: (1) processing AgentX administrative messages (e.g, connection requests from a subagent to a master agent); and (2) processing SNMP messages (e.g., the coordinated actions of a master agent and one or more subagents in processing a received SNMP Get-PDU). 7.1. Processing AgentX Administrative Messages This subsection describes the actions of AgentX protocol entities in processing AgentX administrative messages. Such messages include those involved in establishing and terminating an AgentX session between a subagent and a master agent, those by which a subagent reserves instance index values, and those by which a subagent communicates to a master agent which MIB regions it supports. 7.1.1. Processing the agentx-Open-PDU When the master agent receives an agentx-Open-PDU, it processes it as follows: 1) If an AgentX session for this subagent has already been established (via an agentx-Open-PDU from the same transport endpoint), an agentx-Response-PDU is sent with res.error set to 'alreadyOpen'. 2) If the master agent is unable to open an AgentX session for some other reason, it may refuse the session establishment request, sending in reply an agentx-Response-PDU whose res.error field is set to `openFailed'. Daniele/Wijnen Expires May 1997 [Page 38] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 3) Otherwise, the master agent retains session-specific information from the PDU for this subagent: - The subagent sets the NETWORK_BYTE_ORDER bit to indicate its native byte ordering. If set, all numeric data transmitted during this AgentX session are in network byte order (most significant byte first), else they are transmitted least significant byte first. All PDUs exchanged over this AgentX session will use this byte ordering (including this Open-PDU and its Response-PDU). The Open-PDU is the only one for which the NETWORK_BYTE_ORDER bit has meaning; byte ordering is an attribute of the session, not of each subsequent PDU. (Note: The 12-byte AgentX header is always transmitted in network byte order regardless of how the rest of the PDU is transmitted.) - The o.timeout value is used in calculating timeout conditions for this subagent. - The o.id and o.descr fields are used to create an entry in the agentxSubAgentTable defined in [TBD]. 4) An agentx-Response-PDU is sent with the res.error field set to `noError'. The 4 bytes immediately following the header are encoded with the value of sysUpTime.0 for the default context. At this point, an AgentX session is considered established between the master agent and the subagent. An AgentX session is a distinct channel for the exchange of AgentX protocol messages between a master agent and one subagent, qualified by the session-specific attributes listed in (3) above. Agentx session establishment is initiated by the subagent. An AgentX session can be terminated by either the master agent or the subagent. 7.1.2 Processing the agentx-IndexReserve-PDU Successful processing of this PDU results in the master agent reserving a value for a MIB index exclusively for the requesting subagent. This feature is necessary in situations where multiple subagents instantiate different conceptual rows of the same table. For instance, subagents that represent a single interface in `ifTable' require a unique value of `ifIndex', and so might first reserve a value of `ifIndex' with the master agent. When the master agent receives an agentx-IndexReserve-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with Daniele/Wijnen Expires May 1997 [Page 39] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 res.error set to `notOpen'. 2) Each VarBind in the VarBindList is processed until either all are successful, or one fails. If any VarBind fails, an agentx-Response-PDU is sent in reply containing the original VarBindList, with res.index set to indicate the failed VarBind, and with res.error set as described subsequently. All other VarBinds are ignored; no index values are reserved. VarBinds are processed as follows: - v.name is the name of the index for which a value is to be reserved. - v.type is the syntax of the index object. - v.data indicates the specific index value requested. If the NEW_INDEX or the ANY_INDEX bit is set, the actual value in v.data is ignored and an appropriate index value is generated. a) If v.type is not supported by the master agent, the VarBind fails and res.error is set to `indexUnsupportedType'. Note: A master agent must not return this error code when v.type is INTEGER. b) If there are currently reserved index values for v.name, but the syntax of those values does not match v.type, the VarBind fails and res.error is set to `indexWrongType'. c) Otherwise, if both the NEW_INDEX and ANY_INDEX bits are clear, reservation of a specific index value is being requested. If the requested index is already reserved for v.name, the VarBind fails and res.error is set to `indexAlreadyReserved'. d) Otherwise, if the NEW_INDEX bit is set, but the master agent is not able to generate a next available index value for v.name that has never been reserved, the VarBind fails and res.error is set to `indexNoneAvailable'. e) Otherwise, if the ANY_INDEX bit is set, but the master agent is not able to generate an index value for v.name that either has never been reserved, or that was previously reserved but is not currently, the VarBind fails and res.error is set to `indexNoneAvailable'. 3) If all VarBinds are processed successfully, an agentx-Response-PDU is sent in reply with res.error set to `noError'. A VarBindList is included that is identical to the Daniele/Wijnen Expires May 1997 [Page 40] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 one sent in the agentx-IndexReserve-PDU, except that VarBinds requesting the next available index value are updated with an appropriate value. Note: AgentX index reservation is only loosely coupled to AgentX MIB region registration. It is assumed that the reason for reserving an index value is so that that value can be used in qualifying a MIB region during subsequent registration (for example, to register row 7 of ifTable instead of `ifTable'); however, the state of index reservations is not considered during processing of registration PDUs, and vice versa. 7.1.3 Processing the agentx-IndexUnreserve-PDU The use of this PDU results in the master agent releasing an index value that was previously reserved. When the master agent receives an agentx-IndexUnreserve-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) Each VarBind in the VarBindList is processed until either all are successful, or one fails. If any VarBind fails, an agentx-Response-PDU is sent in reply containing the original VarBindList, with res.index set to indicate the failed VarBind, and with res.error set as described subsequently. All other VarBinds are ignored; no index values are released. VarBinds are processed as follows: - v.name is the name of the index for which a value is to be released - v.type is the syntax of the index object - v.data indicates the specific index value to be released. The NEW_INDEX and ANY_INDEX bits are ignored and should be cleared. a) If the index value for the named index is not currently reserved by this subagent, the VarBind fails and res.error is set to `indexNotReserved'. 3) If all VarBinds are processed successfully, an agentx-Response-PDU is sent in reply with res.error set to `noError'. A VarBindList is included which is identical to the one sent in the agentx-IndexUnreserve-PDU. Daniele/Wijnen Expires May 1997 [Page 41] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 All released index values are now available, and may be used in response to subsequent reservation requests for ANY_INDEX values for the particular index. 7.1.4. Processing the agentx-Register-PDU When the master agent receives an agentx-Register-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) Characterize the request. If r.region (or any of its set of Object Identifiers, if r.range is non-zero) is exactly the same as any currently registered value of r.region (or any of its set of Object Identifiers), this registration is termed a duplicate region. If r.region (or any of its set of Object Identifiers, if r.range is non-zero) is a subtree of, or contains, any currently registered value of r.region (or any of its set of Object Identifiers), this registration is termed an overlapping region. If the NON_DEFAULT_CONTEXT bit is set, this region is to be logically registered within the single context indicated by r.context. Otherwise this region is to be logically registered within the default context. A registration that would result in a duplicate region with the same priority and within an identical context (including the default) as a current registration, is termed a duplicate registration. 3) If the NON_DEFAULT_CONTEXT bit is set, and the master agent supports only a default context, an agentx-Response-PDU is returned with res.error set to `unsupportedContext' and the requested registration fails. Note: A conformant AgentX master agent must support the notion of a default context, and may support non-default contexts. 4) Otherwise, if this is a duplicate registration, an agentx-Response-PDU is returned with res.error set to `duplicateRegistration', and the requested registration fails. 5) Otherwise, an agentx-Response-PDU is returned with res.error set to `noError', and a 4-byte TimeTicks value following the header. The latter is the current value of sysUpTime.0 for Daniele/Wijnen Expires May 1997 [Page 42] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 the context that was indicated in the registration message. The master agent adds this region to its registered OID space for the indicated context, to be considered during the dispatching phase for subsequently received SNMP protocol messages. Note: The following algorithm describes maintaining a set of OID ranges derived from "splitting" registered regions. The algorithm for operational dispatching is also stated in terms of these OID ranges. These OID ranges are a useful explanatory device, but are not required for a correct implementation. - If r.region (R1) is a subtree of a currently registered region (R2), split R2 into 3 new regions (R2a, R2b, and R2c) such that R2b is an exact duplicate of R1. Now remove R2 and add R1, R2a, R2b, and R2c to the master agent's lexicographically ordered set of ranges (the registered OID space). Note: Though newly-added ranges R1 and R2b are identical in terms of the MIB objects they contain, they are registered by different subagents, possibly at different priorities. For instance, if subagent S2 registered `ip' (R2 is 1.3.6.1.2.1.4) and subagent S1 subsequently registered `ipNetToMediaTable' (R1 is 1.3.6.1.2.1.4.22), the resulting set of registered regions would be: 1.3.6.1.2.1.4 up to but not including 1.3.6.1.2.1.4.22 (by S2) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S2) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S1) 1.3.6.1.2.1.4.23 up to but not including 1.3.6.1.2.1.5 (by S2) - If r.region (R1) overlaps one or more currently registered regions, then for each overlapped region (R2) split R1 into 3 new ranges (R1a, R1b, R1c) such that R1b is an exact duplicate of R2. Add R1b and R2 into the lexicographically ordered set of regions. Apply (5) above iteratively to R1a and R1c (since they may overlap, or be subtrees of, other regions). For instance, given the currently registered regions in the example above, if subagent S3 now registers mib-2 (R1 is 1.3.6.1.2.1) the resulting set of regions would be: 1.3.6.1.2.1 up to but not including 1.3.6.1.2.1.4 (by S3) 1.3.6.1.2.1.4 up to but not including 1.3.6.1.2.1.4.22 (by S2) 1.3.6.1.2.1.4 up to but not including 1.3.6.1.2.1.4.22 (by S3) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S2) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S1) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S3) Daniele/Wijnen Expires May 1997 [Page 43] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 1.3.6.1.2.1.4.23 up to but not including 1.3.6.1.2.1.5 (by S2) 1.3.6.1.2.1.4.23 up to but not including 1.3.6.1.2.1.5 (by S3) 1.3.6.1.2.1.5 up to but not including 1.3.6.1.2.2 (by S3) Note that at registration time a region may be split into multiple OID ranges due to pre-existing registrations, or as a result of any subsequent registration. This region splitting is transparent to subagents. Hence the master agent must always be able to associate any OID range with the information contained in its original agentx-Register-PDU. 7.1.4.1. Handling Duplicate OID Ranges As a result of this registration algorithm there are likely to be duplicate OID ranges (regions of identical MIB objects registered to different subagents) in the master agent's registered OID space. Whenever the master agent's dispatching algorithm (see 7.2.1, Dispatching AgentX PDUs) selects a duplicate OID range, the determination of which one to use proceeds as follows: 1) Choose the one whose original agentx-Register-PDU r.region contained the most subids, i.e., the most specific r.region. Note: The presence or absence of a range subid has no bearing on how "specific" one object identifier is compared to another. 2) If still ambiguous, there were duplicate regions. Choose the one whose original agentx-Register-PDU specified the smaller value of r.priority. 7.1.5. Processing the agentx-Unregister-PDU 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) If u.region and the indicated context do not match an existing registration of this subagent, an agentx-Response-PDU is returned with res.error set to 'unknownRegistration'. 3) Otherwise, an agentx-Response-PDU is sent in reply with res.error set to `noError', and the previous registration is removed: - The master agent removes u.region from its registered OID space within the indicated context. If the original region had been split, all such related regions are removed. Daniele/Wijnen Expires May 1997 [Page 44] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 For instance, given the example registry above, if subagent S2 unregisters `ip', the resulting registry would be: 1.3.6.1.2.1 up to but not including 1.3.6.1.2.1.4 (by S3) 1.3.6.1.2.1.4 up to but not including 1.3.6.1.2.1.4.22 (by S3) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S1) 1.3.6.1.2.1.4.22 up to but not including 1.3.6.1.2.1.4.23 (by S3) 1.3.6.1.2.1.4.23 up to but not including 1.3.6.1.2.1.5 (by S3) 1.3.6.1.2.1.5 up to but not including 1.3.6.1.2.2 (by S3) 7.1.6. Processing the agentx-AddAgentCaps-PDU When the master agent receives an agentx-AddAgentCaps-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, a agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) Otherwise, if the NON_DEFAULT_CONTEXT bit is set, and the master agent supports only a default context, an agentx-Response-PDU is returned with res.error set to `unsupportedContext'. 3) Otherwise, the master agent adds the subagent's capabilities information to the sysORTable for the indicated context. An agentx-Response-PDU is sent in reply with res.error set to `noError'. 7.1.7. Processing the agentx-RemoveAgentCaps-PDU 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) If the combination of a.id and the optional a.context does not represent a sysORTable entry that was added by this subagent, an agentx-Response-PDU is returned with res.error set to 'unknownAgentCaps'. 3) Otherwise the master agent deletes the corresponding sysORTable entry and sends in reply an agentx-Response-PDU with res.error set to 'noError'. 7.1.8. Processing the agentx-Close-PDU When the master agent receives an agentx-Close-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with Daniele/Wijnen Expires May 1997 [Page 45] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 res.error set to `notOpen'. 2) Otherwise, the master agent closes the AgentX session as described below. No agentx-Response-PDU is sent. - All MIB regions that have been registered by this subagent are unregistered, as described in 7.1.5. - All index values reserved by this subagent are freed, as described in section 7.1.3. - All sysORID values being exported on behalf of this subagent are removed, as described in section 7.1.7. When a subagent receives an agentx-Close-PDU, it must reestablish an AgentX session and reregister its MIB regions. 7.1.9. Detecting Connection Loss If a master agent is able to detect (from the underlying transport) that a subagent cannot receive AgentX PDUs, it should close the AgentX session as described in 7.1.8, step (2). 7.1.10. Processing the agentx-Notify-PDU A subagent sending SNMPv1 trap information must map this into (minimally) a value of snmpTrapOID.0, as described in 3.1.2 of RFC 1908 [8]. When the master agent receives an agentx-Notify-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) The VarBindList is parsed. If it does not contain a value for sysUpTime.0, the master agent supplies the current value of sysUpTime.0. 3) Notifications are sent according to the implementation-specific configuration of the master agent. If SNMPv1 Trap PDUs are generated, the recommended mapping is as described in FYI V2ToV1 [9]. No agentx-Response-PDU is sent. Daniele/Wijnen Expires May 1997 [Page 46] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 7.1.11. Processing the agentx-Ping-PDU When the master agent receives an agentx-Ping-PDU, it processes it as follows: 1) If an AgentX session for this subagent has not been established, an agentx-Response-PDU is sent in reply with res.error set to `notOpen'. 2) Otherwise, an agentx-Response-PDU is sent, whose res.error field is noError(0), and containing no other data. 7.2. Processing Received SNMP Protocol Messages When an SNMP GetRequest, GetNextRequest, GetBulkRequest, or SetRequest protocol message is received by the master agent, the master agent applies its access control policy. In particular, for SNMPv1 or SNMPv2c PDUs, the master agent applies the Elements of Procedure defined in section 4.1 of RFC 1157 [6] that apply to receiving entities. (For other versions of SNMP, the master agent applies the access control policy defined in the Elements of Procedure for those versions.) In the SNMPv1 or v2c frameworks, the master agent uses the community string as an index into a local repository of configuration information that may include community profiles or more complex context information. If application of the access control policy results in a valid SNMP request PDU, then an SNMP Response-PDU is constructed from information gathered in the exchange of AgentX PDUs between the master agent and one or more subagents. Upon receipt and initial validation of an SNMP request PDU, a master agent uses the procedures described below to dispatch AgentX PDUs to the proper subagents, marshal the subagent responses, and construct an SNMP response PDU. 7.2.1. Dispatching AgentX PDUs Upon receipt and initial validation of an SNMP request PDU, a master agent uses the procedures described below to dispatch AgentX PDUs to the proper subagents. Note: In the following procedures, an object identifier is said to be "contained" within an OID range when both of the following are true: - The object identifier does not lexicographically precede the range. Daniele/Wijnen Expires May 1997 [Page 47] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 - The object identifier lexicographically precedes the end of the range. 7.2.1.1. agentx-Get-PDU An SNMP Response-PDU is constructed whose fields all contain the same values as in the SNMP Request-PDU, except that the value of each variable binding is set to 'noSuchObject'. Each variable binding in the Request-PDU is processed in order, as follows: (1) Identify the target OID range. Within a lexicographically ordered set of OID ranges, valid for the indicated context, locate the region that contains the binding's name. (2) If no such OID range exists the variable binding is not processed further, and retains its initialized value (`noSuchObject'). (3) Identify the single subagent responsible for this OID range, termed the target subagent. (4) Determine the timeout value for this OID range, which is a) the value specified during registration of the region containing the OID range, if it was non-zero b) otherwise, the value specified during the target subagent's AgentX session establishment, if it was non-zero c) otherwise, the master agent's default value (5) If this is the first variable binding to be dispatched to the target subagent in a request/response exchange entailed in the processing of this management request: - Create an agentx-Get-PDU for the subagent, with the header fields initialized as described above (see 6.1 AgentX PDU Header). - If the master agent has determined that a specific non-default context is associated with the Request-PDU, that context is encoded into g.context and the NON_DEFAULT_CONTEXT bit is set in h.flags. Otherwise, no context Octet String is added to the PDU, and the NON_DEFAULT_CONTEXT bit is cleared. Daniele/Wijnen Expires May 1997 [Page 48] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 (6) Add a SearchRange to the end of the target subagent's PDU for this variable binding. - The variable binding's name is encoded into the starting OID. - The ending OID is encoded as null. 7.2.1.2. agentx-GetNext-PDU An SNMP Response-PDU is constructed whose fields all contain the same values as in the SNMP Request-PDU, except that the value of each variable binding is set to 'endOfMibView'. Each variable binding in the Request-PDU is processed in order, as follows: (1) Identify the target OID range. Within a lexicographically ordered set of OID ranges, valid for the indicated context, locate a) the OID range that contains the variable binding's name and is not a fully qualified instance, or b) the OID range that is the first lexicographical successor to the variable binding's name. (2) If no such OID range exists the variable binding is not processed further, and retains its initialized value (`endOfMibView'). (3) Identify the single subagent responsible for this OID range, termed the target subagent. (4) Determine the timeout value for this OID range, which is a) the value specified during registration of the region containing the OID range, if it was non-zero b) otherwise, the value specified during the target subagent's AgentX session establishment, if it was non-zero c) otherwise, the master agent's default value (5) If this is the first variable binding to be dispatched to the target subagent in a request/response exchange entailed in the processing of this management request: - Create an agentx-GetNext-PDU for the subagent, with the header fields initialized as described above (see 6.1 AgentX PDU Header). Daniele/Wijnen Expires May 1997 [Page 49] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 - If the master agent has determined that a specific non-default context is associated with the Request-PDU, that context is encoded into g.context and the NON_DEFAULT_CONTEXT bit is set in h.flags. Otherwise, no context Octet String is added to the PDU, and the NON_DEFAULT_CONTEXT bit is cleared. (6) Add a SearchRange to the end of the target subagent's agentx-GetNext-PDU for this variable binding. - if (1a) applies, the variable binding's name is encoded into the starting OID, and the OID's `include' field is set to 0. - if (1b) applies, the target OID is encoded into the starting OID, and its `include' field is set to 1. - the ending OID is encoded with the OID range that is the first lexicographical successor to the target OID range, and that was not registered by the target subagent. If no such OID range exists, it is encoded as a null OID. 7.2.1.3. agentx-GetBulk-PDU (Note: The outline of the following procedure is based closely on section 4.2.3, "The GetBulkRequest-PDU" of RFC 1905 [4]. Please refer to it for details on the format of the SNMP GetBulkRequest-PDU itself.) An SNMP Response-PDU is constructed whose fields all contain the same values as in the SNMP Request-PDU. The SNMP Response-PDU contains N + (M * R) variable bindings whose values are set to `EndOfMibView', where N ("non-repeaters") is the minimum of: a) the value of the non-repeaters field in the request, and b) the number of variable bindings in the request M ("max-repetitions") is the value of the max-repetitions field in the request R ("repeaters") is the maximum of: a) (number of variable bindings in the request) - N, and b) zero Each variable binding in the Request-PDU is processed in order, as follows: (1) Identify the target OID range and target subagent, exactly as described for the agentx-GetNext-PDU (see 7.2.1.2). Daniele/Wijnen Expires May 1997 [Page 50] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 (2) If this is the first variable binding to be dispatched to the target subagent in a request/response exchange entailed in the processing of this management request: - Create an agentx-GetBulk-PDU for the subagent, with the header fields initialized as described above (see 6.1 AgentX PDU Header). - If the master agent has determined that a specific non-default context is associated with the Request-PDU, that context is encoded into g.context and the NON_DEFAULT_CONTEXT bit is set in h.flags. Otherwise, no context Octet String is added to the PDU, and the NON_DEFAULT_CONTEXT bit is cleared. - Set g.non_repeaters to 0. - g.max_repetitions is generally set to the max_repetitions value in the Request-PDU. However, the master agent may elect a smaller value based on the maximum possible size of a potential Response-PDU, known constraints of the AgentX transport, or any other implementation-specific constraint. (3) Add a SearchRange to the end of the target subagent's agentx-GetBulk-PDU for this variable binding, as described for the agentx-GetNext-PDU. If the variable binding was within the non_repeaters range in the original Request-PDU, increment the value of g.non_repeaters. 7.2.1.4. agentx-TestSet-PDU AgentX employs the well-known test-commit-undo-cleanup phases to achieve "as if simultaneous" semantics of the SNMP SetRequest-PDU within the extensible agent. The initial phase involves the agentx-TestSet-PDU. An SNMP Response-PDU is constructed whose fields all contain the same values as in the SNMP Request-PDU. Each variable binding in the Request-PDU is processed in order, as follows: (1) Identify the target OID range. Within a lexicographically ordered set of OID ranges, valid for the indicated context, locate the range that contains the variable binding's name. (2) If no such OID range exists, the SNMP Response-PDU is modified to indicate this variable binding failed with `noAccess', and Daniele/Wijnen Expires May 1997 [Page 51] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 processing is complete for this request. (3) Identify the single subagent responsible for this OID range, termed the target subagent. (4) Determine the timeout value for this OID range, which is a) the value specified during registration of the region containing the OID range, if it was non-zero b) otherwise, the value specified during the target subagent's AgentX session establishment, if it was non-zero c) otherwise, the master agent's default value (5) If this is the first variable binding to be dispatched to the target subagent in a request/response exchange entailed in the processing of this management request: - create an agentx-TestSet-PDU for the subagent, with the header fields initialized as described above (see 6.1 AgentX PDU Header). - If the master agent has determined that a specific non-default context is associated with the Request-PDU, that context is encoded into t.context and the NON_DEFAULT_CONTEXT bit is set in h.flags. Otherwise, no context Octet String is added to the PDU, and the NON_DEFAULT_CONTEXT bit is cleared. (6) Add a VarBind to the end of the target subagent's PDU for this variable binding, as described in section 5.4. 7.2.1.5. Dispatch A timeout value is calculated for each PDU to be sent, which is the maximum value of the timeouts associated for each of the PDU's SearchRanges (as described above). 7.2.2. Subagent Processing of agentx-Get, GetNext, GetBulk-PDUs When a subagent receives an agentx-Get-, GetNext-, or GetBulk-PDU, it performs the indicated management operations and returns an agentx-Response-PDU. The agentx-Response-PDU header fields are identical to the received request PDU except that, at the start of processing, the subagent initializes h.type to Response, res.error to `noError', res.error_index to 0, and the VarBindList to null. Daniele/Wijnen Expires May 1997 [Page 52] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 Each SearchRange in the request PDU is then processed in order, and a corresponding VarBind is added to the agentx-Response-PDU as described below. If processing should fail for any reason not described below, res.error is set to `genErr', res.error_index to the index of the failed SearchRange, the VarBindList is reset to null, and this agentx-Response-PDU is returned to the master agent. 7.2.2.1. Subagent Processing of the agentx-Get-PDU Upon the subagent's receipt of an agentx-Get-PDU, each SearchRange in the request is processed in order as follows: (1) The starting OID is copied to v.name. (2) If the starting OID exactly matches the name of a variable instantiated by this subagent within the indicated context, v.type and v.data are encoded to represent the variable's syntax and value, as described in section 5.4, Value Representation. (3) Otherwise, if the starting OID does not match the object identifier prefix of any variable instantiated within the indicated context, the VarBind is set to `noSuchObject', in the manner described in section 5.4, Value Representation. (4) Otherwise, the VarBind is set to `noSuchInstance' in the manner described in section 5.4, Value Representation. 7.2.2.2. Subagent Processing of the agentx-GetNext-PDU Upon the subagent's receipt of an agentx-GetNext-PDU, each SearchRange in the request is processed in order as follows: (1) The subagent searches for a variable within the lexicographically ordered list of variable names for all variables it instantiates (without regard to registration of regions) within the indicated context, for which the following are all true: - if the `include' field of the starting OID is 0, the variable's name is the closest lexicographical successor to the starting OID. - if the `include' field of the starting OID is 1, the variable's name is either equal to, or the closest lexicographical successor to, the starting OID. - If the ending OID is not null, the variable's name lexicographically precedes the ending OID. If all of these conditions are met, v.name is set to the Daniele/Wijnen Expires May 1997 [Page 53] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 located variable's name. v.type and v.data are encoded to represent the variable's syntax and value, as described in section 5.4, Value Representation. (2) If no such variable exists, v.name is set to the starting OID, and the VarBind is set to `endOfMibView', in the manner described in section 5.4, Value Representation. 7.2.2.3. Subagent Processing of the agentx-GetBulk-PDU A maximum of N + (M * R) VarBinds are returned, where N equals g.non_repeaters, M equals g.max_repetitions, and R is (number of SearchRanges in the GetBulk request) - N. The first N SearchRanges are processed exactly as for the agentx-GetNext-PDU. If M and R are both non-zero, the remaining R SearchRanges are processed iteratively to produce potentially many VarBinds. For each iteration i, such that i is greater than zero and less than or equal to M, and for each repeated SearchRange s, such that s is greater than zero and less than or equal to R, the (N+((i-1)*R)+s)-th VarBind is added to the agentx-Response-PDU as follows: 1) The subagent searches for a variable within the lexicographically ordered list of variable names for all variables it instantiates (without regard to registration of regions) within the indicated context, for which the following are all true: - The variable's name is the (i)-th lexicographical successor to the (N+s)-th requested OID. (Note that if i is 0 and the `include' field is 1, the variable's name may be equivalent to, or the first lexicographical successor to, the (N+s)-th requested OID.) - If the ending OID is not null, the variable's name lexicographically precedes the ending OID. If all of these conditions are met, v.name is set to the located variable's name. v.type and v.data are encoded to represent the variable's syntax and value, as described in section 5.4, Value Representation. Daniele/Wijnen Expires May 1997 [Page 54] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 2) If no such variable exists, the VarBind is set to `endOfMibView' as described in section 5.4, Value Representation. v.name is set to v.name of the (N+((i-2)*R)+s)-th VarBind unless i is currently 1, in which case it is set to the value of the starting OID in the (N+s)-th SearchRange. Note that further iterative processing should stop if - For any iteration i, all s values of v.type are `endOfMibView'. - An AgentX transport constraint or other implementation-specific constraint is reached. 7.2.3. Subagent Processing of agentx-TestSet, -CommitSet, -UndoSet, -CleanupSet-PDUs These four PDUs are used to collectively perform the indicated management operation. An agentx-Response-PDU is sent in reply to each of the PDUs, to inform the master agent of the state of the operation. The agentx-Response-PDU header fields are identical to the received request PDU except that, at the start of processing, the subagent initializes h.type to Response, res.error to `noError', and res.error_index to 0. These Response-PDUs do not contain a VarBindList. 7.2.3.1. Subagent Processing of the agentx-TestSet-PDU Upon the subagent's receipt of an agentx-TestSet-PDU, each VarBind in the PDU is validated until they are all successful, or until one fails, as described in section 4.2.5 of RFC 1905 [4]. If each VarBind is successful, the subagent has a further responsibility to ensure the availability of all resources (memory, write access, etc.) required for successfully carrying out a subsequent agentx-CommitSet operation. If this cannot be guaranteed, the subagent should set res.error to resourceUnavailable(13). As a result of this validation step, an agentx-Response-PDU is sent in reply whose res.error field is set to one of the following (SNMPv2 SMI) values: noError (0), genErr (5), noAccess (6), wrongType (7), Daniele/Wijnen Expires May 1997 [Page 55] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 wrongLength (8), wrongEncoding (9), wrongValue (10), noCreation (11), inconsistentValue (12), resourceUnavailable (13), notWritable (17), inconsistentName (18) If this value is not noError(0), the res.index field must be set to the index of the VarBind for which validation failed. Implementation of rigorous validation code may be one of the most demanding aspects of subagent development. Implementors are strongly encouraged to do this right, so as to avoid if at all possible the extensible agent's having to return "commitFailed" or "undoFailed" during subsequent processing. 7.2.3.2. Subagent Processing of the agentx-CommitSet-PDU The agentx-CommitSet-PDU indicates that the subagent should actually perform (as described in the post-validation sections of 4.2.5 of RFC 1905 [4]) the management operation indicated by the previous TestSet-PDU. After carrying out the management operation, the subagent sends in reply an agentx-Response-PDU whose res.error field is set to one of the following (SNMPv2 SMI) values: noError (0), commitFailed (14) If this value is commitFailed(14), the res.index field must be set to the index of the VarBind for which the operation failed. Otherwise res.index is set to 0. 7.2.3.3. Subagent Processing of the agentx-UndoSet-PDU The agentx-UndoSet-PDU indicates that the subagent should undo the management operation requested in a preceding CommitSet-PDU. The undo process is as described in section 4.2.5 of RFC 1905 [4]. After carrying out the undo process, the subagent sends in reply an agentx-Response-PDU whose res.index field is set to 0, and whose res.error field is set to one of the following (SNMPv2 SMI) values: noError (0), undoFailed (15) This ends subagent processing of the management request. Daniele/Wijnen Expires May 1997 [Page 56] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 7.2.3.4. Subagent Processing of the agentx-CleanupSet-PDU The agentx-CleanupSet-PDU signals the end of processing of the management operation requested in the previous CommitSet-PDU. This is an indication to the subagent that it may now release any resources it may have reserved in order to carry out the management request. No response is sent by the subagent. 7.2.4. Master Agent Processing of AgentX Responses The master agent now marshals all subagent agentx-Response-PDUs and builds an SNMP Response-PDU. In the next several sub-sections, the initial processing of all subagent agentx-Response-PDUs is described, followed by descriptions of subsequent processing for each specific subagent Response. 7.2.4.1. Common Processing of All AgentX Response PDUs 1) If a subagent does not respond within the timeout interval for this dispatch, it is treated as if the subagent had returned `genErr' and processed as described below. A timeout may be due to a variety of reasons, and does not necessarily denote a failed or malfunctioning subagent. As such, the master agent's response to a subagent timeout is implementation-specific, but with the following constraint: A subagent that times out on three consecutive requests is considered unable to respond, and the master agent must close the AgentX session as described in 7.1.8, step (2). 2) Otherwise, if the h.ID field of an agentx-Response-PDU does not match that of the request PDU sent to this subagent, the PDU is ignored. 3) Otherwise, the responses are processed jointly to form the SNMP Response-PDU. 7.2.4.2. Processing of Responses to agentx-Get-PDUs After common processing of the subagent's response to an agentx-Get-PDU (see 7.2.4.1 above), processing continues with the following steps: 1) For any received agentx-Response-PDU, if res.error is not `noError', the SNMP response PDU's error code is set to this value, and its error index to the index of the variable binding Daniele/Wijnen Expires May 1997 [Page 57] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 corresponding to the failed VarBind in the subagent's agentx-Response-PDU. All other agentx-Response-PDUs received due to processing this SNMP Request are ignored. Processing is complete; the SNMP Response PDU is ready to be sent (see section 7.2.5, Sending the SNMP Response-PDU). 2) Otherwise, the content of each VarBind in the agentx-Response-PDU is used to update the corresponding variable binding in the SNMP Response-PDU. 7.2.4.3. Processing of Responses to agentx-GetNext- and agentx-GetBulk-PDUs After common processing of the subagent's response to an agentx-GetNext-PDU or agentx-GetBulk-PDU (see 7.2.4.1 above), processing continues with the following steps: 1) For any received agentx-Response-PDU, if res.error is not `noError', the SNMP response PDU's error code is set to this value, and its error index to the index of the variable binding corresponding to the failed VarBind in the subagent's agentx-Response-PDU. All other agentx-Response-PDUs received due to processing this SNMP Request are ignored. Processing is complete; the SNMP Response PDU is ready to be sent (see section 7.2.5, Sending the SNMP Response-PDU). 2) Otherwise, the content of each VarBind in the agentx-Response-PDU is used to update the corresponding variable binding in the SNMP Response-PDU. After all expected agentx-Response-PDUs have been processed, if any variable bindings still contain the value `endOfMibView', processing must continue: 3) For each such variable binding, a target OID range is identified which is the lexicographical successor to the target OID range for this variable binding on the last iteration. The target subagent is the one that registered the target OID range. 4) If this is the first variable binding to be dispatched to the target subagent in this request/response exchange, create an agentx-GetNext or GetBulk-PDU for the subagent, with the header and context fields initialized as described previously for these PDUs. Daniele/Wijnen Expires May 1997 [Page 58] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 5a) For responses to agentx-GetNext-PDUs: i) Add a SearchRange to the end of the target subagent's PDU for this variable binding. The starting OID is set to the target OID range, and its `include' field is set to 1. The ending OID is set to the OID range that is the first lexicographical successor to the target OID range, and that was not registered by the target subagent. If no such OID range exists, the ending OID is set to null. 5b) For responses to agentx-GetBulk-PDUs: i) Set the value of g.non_repeaters and g.max_repetitions to 0. ii) Add a SearchRange to the end of the target subagent's PDU for this variable binding. The starting OID is set to the target OID range, and its `include' field is set to 1. The ending OID is set to the OID range that is the first lexicographical successor to the target OID range, and that was not registered by the target subagent. If no such OID range exists, the ending OID is set to null. iii) If the variable binding was within the non_repeaters range in the original Request-PDU, increment the value of g.non_repeaters. Otherwise, set the value of g.max_repetitions to the maximum of its current value, or the number of response variable bindings still required for this requested variable binding. 6) The AgentX PDUs are sent to the subagent(s), and the responses are received and processed according to the steps described in section 7.2.4. 7) This process continues iteratively until a complete SNMP Response-PDU has been built, or until there remain no target OID range lexicographical successors. << << TBD: Include example << 7.2.4.4. Processing of Responses to agentx-TestSet-PDUs After common processing of the subagent's response to an agentx-TestSet-PDU (see 7.2.4.1 above), processing continues with the following steps: Daniele/Wijnen Expires May 1997 [Page 59] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 1) If any target subagent's response is not `noError', all other agentx-Response-PDUs received due to processing this SNMP Request are ignored. An agentx-CleanupSet-PDU is sent to each target subagent. Processing is complete; the SNMP Response-PDU is constructed as described below in 7.2.4.6, step (2). 2) Otherwise an agentx-CommitSet-PDU is sent to each target subagent. 7.2.4.5. Processing of Responses to agentx-CommitSet-PDUs After common processing of the subagent's response to an agentx-CommitSet-PDU (see 7.2.4.1 above), processing continues with the following steps: 1) If any response is not `noError', all other agentx-Response-PDUs received due to processing this SNMP Request are ignored. An agentx-UndoSet-PDU is sent to each target subagent. 2) Otherwise an agentx-CleanupSet-PDU is sent to each target subagent. Processing is complete; the SNMP Response-PDU is constructed as described below in 7.2.4.6, step (2). 7.2.4.6. Processing of Responses to agentx-UndoSet-PDUs After common processing of the subagent's response to an agentx-UndoSet-PDU (see 7.2.4.1 above), processing continues with the following steps: 1) An agentx-CleanupSet-PDU is sent to each target subagent. 2) If any response is not `noError' the SNMP response PDU's error code is set to this value, and its error index to the index of the variable binding corresponding to the failed VarBind in the agentx-TestSet-PDU. Otherwise the SNMP Response-PDU's error code is set to `noError' and its error index to 0. 7.2.5. Sending the SNMP Response-PDU Once the processing described in sections 7.2.1 - 7.2.4 is complete, there is an SNMP Response-PDU available. The master agent now implements the Elements of Procedure for the applicable version of the SNMP protocol in order to encapsulate the PDU into a message, Daniele/Wijnen Expires May 1997 [Page 60] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 and transmit it to the originator of the SNMP management request. Note that this may involve altering the PDU contents (for instance, to replace the original variable bindings if an error condition is to be returned). The Response-PDU may also be altered in order to support the SNMP version 1 framework. In such cases the required mapping is that defined in FYI V2ToV1 [9]. (Note in particular that the rules for handling Counter64 syntax may require resending AgentX PDUs until a VarBind of suitable syntax is returned.) 7.2.6. MIB Views AgentX subagents are not aware of MIB views, since view information is not contained in AgentX PDUs. As stated above, the descriptions of procedures in section 7 of this memo are not intended to constrain the internal architecture of any conformant implementation. In particular, the master agent procedures described in sections 7.2.1 and 7.2.4 may be altered so as to optimize AgentX exchanges when implementing MIB views. Such optimizations are beyond the scope of this memo. But note that section 7.2.3 defines subagent behavior in such a way that alteration of SearchRanges may be used in such optimizations. 8. Transport Mappings The same AgentX PDU formats, encodings, and elements of procedure are used regardless of the underlying transport. 8.1. AgentX over TCP 8.1.1. Well-known Values The master agent accepts TCP connection requests for the well-known port [TBD]. Subagents connect to the master agent using this port number. 8.1.2. Operation Once a TCP connection has been established, the AgentX peers use this connection to carry all AgentX PDUs. Only a single logical connection may be established per transport connection. All AgentX PDUs are presented individually to the TCP, to be sent as the data portion of a TCP PDU. Daniele/Wijnen Expires May 1997 [Page 61] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 8.2. AgentX over UNIX-domain Sockets Many (BSD-derived) implementations of the UNIX operating system support the UNIX pathname address family (AF_UNIX) for socket communications. This provides a convenient method of sending and receiving data between processes on the same host. Mapping AgentX to this transport is useful for environments that - wish to guarantee subagents are running on the same managed node as the master agent, and where - sockets provide better performance than TCP or UDP, especially in the presence of heavy network I/O 8.2.1. Well-known Values The master agent creates a well-known UNIX-domain socket endpoint called "var/agentx/master". (It may create other, implementation-specific endpoints.) This endpoint name uses the character set encoding native to the managed node, and represents a UNIX-domain stream (SOCK_STREAM) socket. 8.2.2. Operation Once a connection has been established, the AgentX peers use this connection to carry all AgentX PDUs. Only a single logical connection may be established per transport connection. All AgentX PDUs are presented individually to the socket layer, to be sent in the data stream. 9. Security Considerations This memo defines a protocol between two processing entities, one of which (the master agent) is also assumed to perform authentication of received SNMP requests and to control access to management information. The master agent performs these security operations independently of the other processing entity (the subagent). Thus, security issues are outside the scope of this protocol definition. 10. Acknowledgements The initial draft of this memo was heavily influenced by the DPI 2.0 specification RFC 1592 [7]. Daniele/Wijnen Expires May 1997 [Page 62] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 This document was produced by the IETF Agent Extensibility (AgentX) Working Group, and benefited especially from the contributions of the following working group members: David Battle, Jeff Case, Maria Greene, Dave Keeney, Bob Natale, Randy Presuhn, Aleksey Romanov, Don Ryan, and Juergen Schoenwaelder. 11. Questions and Issues 11.1 Design The consensus is to proceed with multiple variables per PDU. If we need to go back and revisit this, the thinking is to provide a choice at connection time, allowing the subagent to choose either one varbind per PDU or all varbinds per PDU. 11.2 Miscellaneous Issues/Decisions 1) How to transfer binary OIDs? The current encoding is unchanged in this version of this memo. 2) Unionized registrations Removed by consensus in this version. 3) Contexts Consensus was to remove "all". It's either the default, or non-default. Non-default is an Octet String of any length (including 0). 4) sysUpTime Returned with the response to an Open or Register PDU. For Register, it's the value within the specified context. 5) sysORTable This information moved to specific PDUs. 6) SNMP version in the AgentX header Removed by consensus in this version. 7) Options The following optional features are allowed by this memo. Daniele/Wijnen Expires May 1997 [Page 63] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 The decision of whether or not to support these features is implementation specific. Master agent: - Supporting non-default contexts - Supporting next-available-index reservation for non-integer indexes Subagent: none 8) Index reservation - Do index reservations need to be per context? - There is currently no *guaranteed* mechanism for a subagent that closes its AgentX session to re-connect and acquire the previously reserved indexes. Is this an problem? 9) States Haven't specified any yet; may need Test/Commit/Undo/cleanup to finish before other requests are forwarded to a subagent? 10) SNMP request identifier In the normal case, AgentX processing results in a single agentx PDU being sent to any particular subagent while processing an SNMP request. It is possible however for a subagent to receive multiple PDUs during the processing of a single SNMP request. (Subs A and B each are dispatched to while processing a request. A returns endOfMibView for a variable and when the variable is redispatched, it get sent to B.) There is currently no information carried in AgentX that would inform the subagent that this PDU is part of processing the same SNMP request that a previous PDU was. We're not sure that this is an issue. Possible solutions discussed were: 1) Add a request-id field to the request PDUs. 2) Structure h.ID so that the first 3 bytes are unique packet ids, and the last byte counts the number of PDUs sent to a particular subagent per SNMP request. Thus h.ID is still always unique per packet, but carries an implicit notion of Daniele/Wijnen Expires May 1997 [Page 64] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 SNMP request id. 3) Use a bit in h.flags to indicate NEW_SNMP_REQUEST or SAME_SNMP_REQUEST. (Won't work for master agents that service multiple SNMP requests concurrently.) 11) Session ID We don't carry a session/connection identifier in the protocol. It's not an issue currently, because transports we've provided mappings for are connection oriented, and we've specified a single session per transport connection. So AgentX peers can map transport information -> session. Mapping transport info -> AgentX sessions can be done for other transports as well (UDP, shared memory, etc.). So it seems like the use of a session identifier would ultimately be to support multiple AgentX sessions on a single transport connection (as in HTTP). From Don Ryan: The reason I added the Connection Identifier was to separate the subagent logical connection and transport connection. This allows connectionless protocol support but also helps limit the number of connections a subagent shim needs to open. Each connection to the shim can be represented as a logical connection to the AgentX master agent piggybacking on the same transport connection. I found it very useful myself. 12) Traps What traps (if any) should be generated when subagents open/close or modify sysORTable? 11.3 New in this version 1) Octet String A specific encoding rule for octet strings. 2) NETWORK_BYTE_ORDER bit Subagent declares its preferred (native) ordering in the Open-PDU. 3) IndexUnreserve-PDU and "new vs. any" semantics for reservation. 4) AddAgentCaps and RemoveAgentCaps PDUs for transmitting sysORTable information. Daniele/Wijnen Expires May 1997 [Page 65] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 5) Added (DPI) reason codes for Close-PDU. 6) Removed reason code from Unregister-PDU. 12. Authors' and Editor's Addresses Mike Daniele Digital Equipment Corporation 110 Spit Brook Rd Nashua, NH 03062 EMail: daniele@zk3.dec.com Bert Wijnen IBM Professional Services Watsonweg 2 1423 ND Uithoorn The Netherlands Phone: +31-79-322-8316 EMail: wijnen@vnet.ibm.com Dale Francisco (editor) Cisco Systems 150 Castilian Dr Goleta CA 93117 Phone: +1-805-961-3642 Fax: +1-805-961-3600 EMail: dfrancis@cisco.com 13. References [1] Information processing systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), International Organization for Standardization. International Standard 8824, (December, 1987). [2] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1902, January 1996. [3] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Textual Conventions for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1903, January 1996. Daniele/Wijnen Expires May 1997 [Page 66] agentx protocol 00.05 Mon Nov 4 13:16:42 PST 1996 [4] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996. [5] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Management Information Base for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1907, January 1996. [6] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, SNMP Research, Performance Systems International, MIT Laboratory for Computer Science, May 1990. [7] Wijnen, B., Carpenter, G., Curran, K., Sehgal, A., and G. Waters, "Simple Network Management Protocol: Distributed Protocol Interface, Version 2.0", RFC 1592, T.J. Watson Research Center, IBM Corp., Bell Northern Research, Ltd., March 1994. [8] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Coexistence between Version 1 and Version 2 of the Internet-standard Network Management Framework", RFC 1908, January 1996. [9] Wijnen, B., and Levi, D., "V2ToV1: Mapping SNMPv2 onto SNMPv1 Within a Bilingual SNMP Agent", FYI ???, T.J. Watson Research Center, IBM Corp., SNMP Research, Inc., August 1996. [10] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Conformance Statements for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1904, January 1996. Daniele/Wijnen Expires May 1997 [Page 67]   Delivery-Date: Thu, 14 Nov 1996 16:56:38 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id QAA24253 for X-agentx; Thu, 14 Nov 1996 16:56:38 -0800 (PST) Received: from stratacom.strata.com (stratacom.strata.com [204.179.0.2]) by fv.com (8.7.4/8.7.3) with SMTP id QAA24250 for ; Thu, 14 Nov 1996 16:56:37 -0800 (PST) Received: from Strata.COM (kiwi.strata.com) by stratacom.strata.com (4.1/SMI-4.1/Gatekeeper.Strata.Com-950201) id AA12547; Thu, 14 Nov 96 16:56:29 PST Received: from santa.strata.com (santa-le1) by Strata.COM (4.1/SMI-4.1/StrataCom-GCA-Kiwi-931007-1) id AA11716; Thu, 14 Nov 96 16:54:31 PST Received: from marvell.strata.com by santa.strata.com (4.1/SMI-4.1/StrataCom-GCA-SunClient-LOCAL-931101) id AA04194; Thu, 14 Nov 96 16:56:28 PST Date: Thu, 14 Nov 96 16:56:28 PST From: dfrancis@stratacom.com (Dale Francisco) Message-Id: <9611150056.AA04194@santa.strata.com> To: agentx@fv.com Subject: Discussion of AgentX protocol draft ver 00.05 A little over a week ago I posted the latest-and-greatest version of the AgentX protocol draft (version 00.05). If anyone has any questions, or suggestions for improvements, please post them soon, as I will be submitting a final draft to the IETF on or before Tuesday, 26 November. In order to make that deadline, I'd like to set a cutoff date for further comments of Friday, 22 November. Thanks, Dale Francisco Editor, AgentX WG dfrancis@cisco.com Cisco Systems (StrataCom Division) 150 Castilian Drive Goleta CA 93117-3028 voice: (805) 961-3642 fax: (805) 961-3600   Delivery-Date: Fri, 15 Nov 1996 14:37:56 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id OAA06844 for X-agentx; Fri, 15 Nov 1996 14:37:56 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id OAA06841 for ; Fri, 15 Nov 1996 14:37:55 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA22420 for ; Fri, 15 Nov 1996 17:39:28 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma022392; Fri, 15 Nov 96 14:39:00 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id OAA03751 for ; Fri, 15 Nov 1996 14:39:01 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA22386 for ; Fri, 15 Nov 1996 17:38:58 -0500 (EST) Received: from mail4.microsoft.com(131.107.3.29) by gauntlet.fv.com via smap (3.2) id xma022363; Fri, 15 Nov 96 14:38:45 -0800 Received: by mail4.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD302.7F4EB300@mail4.microsoft.com>; Fri, 15 Nov 1996 14:37:16 -0800 Message-ID: From: Don Ryan To: "'dfrancis@stratacom.com'" Cc: "'agentx@fv.com'" Subject: RE: Discussion of AgentX protocol draft ver 00.05 Date: Fri, 15 Nov 1996 14:36:34 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 17 TEXT I agree with the removal of the agent capabilities (sysORTable) OID from the agentx-Open-PDU. I am wondering, though, what happens in the case of overlapping registrations that have different capabilities. The subagent is the only entity which can map the sysORTable OID to one or more of it's registered MIB regions but it has no concept of whether or not all or part of it's registered MIB region is hidden by another subagent at a higher priority. Instead of agentx-AddAgentCaps and agentx-RemoveAgentCaps, should we have just a agentx-GetAgentCaps-PDU which takes a context and MIB range as input and returns a agentx-Response-PDU with the OID of the corresponding capabilities statement?   Delivery-Date: Mon, 18 Nov 1996 02:53:21 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id CAA10596 for X-agentx; Mon, 18 Nov 1996 02:53:21 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id CAA10593 for ; Mon, 18 Nov 1996 02:53:20 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id FAA01905 for ; Mon, 18 Nov 1996 05:54:49 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma001901; Mon, 18 Nov 96 02:54:19 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id CAA05233 for ; Mon, 18 Nov 1996 02:54:22 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id FAA01892 for ; Mon, 18 Nov 1996 05:54:18 -0500 (EST) Received: from mail2.microsoft.com(131.107.3.42) by gauntlet.fv.com via smap (3.2) id xma001886; Mon, 18 Nov 96 02:53:50 -0800 Received: by INET-02-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD4FB.84654610@INET-02-IMC.microsoft.com>; Mon, 18 Nov 1996 02:52:20 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: default subagent timeout Date: Mon, 18 Nov 1996 02:52:56 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 4 TEXT if the default subagent timeout cannot be set by an administrator then why expose it? why can't the subagent apply it's default value to each region when it is registered and save the master agent the hassle of having maintain this value?   Delivery-Date: Mon, 18 Nov 1996 02:57:30 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id CAA10844 for X-agentx; Mon, 18 Nov 1996 02:57:30 -0800 (PST) Received: from fsnt.future.futsoft.com ([38.242.192.5]) by fv.com (8.7.4/8.7.3) with SMTP id CAA10841 for ; Mon, 18 Nov 1996 02:57:26 -0800 (PST) Received: from kailash.future.futsoft.com (38.242.192.4) by fsnt.future.futsoft.com (Integralis SMTPRS 1.4) with SMTP id ; Mon, 18 Nov 1996 16:30:35 +0530 Received: from msgate.future.futsoft.com (msgate.future.futsoft.com [10.0.8.4]) by kailash.future.futsoft.com (8.7.1/8.7.1) with SMTP id FAA26996 for ; Mon, 18 Nov 1996 05:11:48 -0500 Received: by msgate.future.futsoft.com with Microsoft Mail id <3290FE40@msgate.future.futsoft.com>; Mon, 18 Nov 96 16:24:32 PST From: ravendrag To: "'agentx@fv.com'" Subject: Has the new draft supposed to be out this month out? Date: Mon, 18 Nov 96 16:22:00 PST Message-Id: <3290FE40@msgate.future.futsoft.com> Encoding: 8 TEXT X-Mailer: Microsoft Mail V3.0 Hi Has the new draft supposed to be out this month released? Please give me the URL/reference for the draft standard. regards ravendra   Delivery-Date: Mon, 18 Nov 1996 03:02:31 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id DAA11259 for X-agentx; Mon, 18 Nov 1996 03:02:31 -0800 (PST) Received: from INET-01-IMC.microsoft.com (mail1.microsoft.com [131.107.3.41]) by fv.com (8.7.4/8.7.3) with SMTP id DAA11256 for ; Mon, 18 Nov 1996 03:02:30 -0800 (PST) Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD4FC.F099A9B0@INET-01-IMC.microsoft.com>; Mon, 18 Nov 1996 03:02:31 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: searchrangelist for get-PDU Date: Mon, 18 Nov 1996 03:03:55 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 3 TEXT Why is there a SearchRangeList in the agentx-Get-PDU? I thought search ranges included two OIDs. Why would you need two OIDs for a GET request?   Delivery-Date: Mon, 18 Nov 1996 03:27:06 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id DAA13281 for X-agentx; Mon, 18 Nov 1996 03:27:06 -0800 (PST) Received: from mail4.microsoft.com (mail4.microsoft.com [131.107.3.29]) by fv.com (8.7.4/8.7.3) with SMTP id DAA13278 for ; Mon, 18 Nov 1996 03:27:05 -0800 (PST) Received: by mail4.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD500.A42A1C00@mail4.microsoft.com>; Mon, 18 Nov 1996 03:29:01 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: description of header id Date: Mon, 18 Nov 1996 03:28:30 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 3 TEXT it might be useful to have more clarification in the draft as to the purpose of the header id especially given the fact the subagent transport of choice is tcp.   Delivery-Date: Mon, 18 Nov 1996 03:30:53 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id DAA13588 for X-agentx; Mon, 18 Nov 1996 03:30:53 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id DAA13585 for ; Mon, 18 Nov 1996 03:30:53 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id GAA02437 for ; Mon, 18 Nov 1996 06:32:21 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma002433; Mon, 18 Nov 96 03:31:52 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id DAA06539 for ; Mon, 18 Nov 1996 03:31:56 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id GAA02424 for ; Mon, 18 Nov 1996 06:31:51 -0500 (EST) Received: from mail1.microsoft.com(131.107.3.41) by gauntlet.fv.com via smap (3.2) id xma002418; Mon, 18 Nov 96 03:31:33 -0800 Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD500.CAA09B20@INET-01-IMC.microsoft.com>; Mon, 18 Nov 1996 03:30:05 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: null o.id & o.descr Date: Mon, 18 Nov 1996 03:31:28 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 2 TEXT we should state whether specifying both a null id and a null descr is allowed. i do not think it should be in order to enforce 7.1.1 step 1.   Delivery-Date: Mon, 18 Nov 1996 04:41:50 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id EAA18726 for X-agentx; Mon, 18 Nov 1996 04:41:49 -0800 (PST) Received: from mail4.microsoft.com (mail4.microsoft.com [131.107.3.29]) by fv.com (8.7.4/8.7.3) with SMTP id EAA18723 for ; Mon, 18 Nov 1996 04:41:49 -0800 (PST) Received: by mail4.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD50B.13D519B0@mail4.microsoft.com>; Mon, 18 Nov 1996 04:43:43 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: agentx-IndexReserve-PDU Date: Mon, 18 Nov 1996 04:43:13 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 43 TEXT I do not see how a master agent can be "MIB ignorant" yet know how to allocate new (or any) instances of an index. The comments for this PDU mentions "if v.type is not supported by the master agent" which does not seem very extensible to me. How about: a.) subagent A registers MIB region M containing table T and sets FLAG_ACCEPT_EXTENSIONS to TRUE. b.) subagent B asks master agent for an index in table T c.) since table T is in region M and subagent A accepts extensions master agent forwards request to subagent A (the highest priority dude wins here as in all other cases). in this request the master agent includes something to identify subagent B. d.) subagent A responds to the master agent with the reserved index subagent B requested e.) master agent forwards the reponse to subagent B along with the subagent id of subagent A f.) subagent B registers MIB region with new index and set FLAG_IS_EXTENSION to TRUE Note the master agent does not keep any state expect for an id of each connected subagent. If any subagent closes unexpectedly which registered an extension to another subagent's MIB region, then all extensible subagents will receive an agentx-IndexCleanup-PDU with the id of the dead subagent. The extensible subagents should cleanup all of the resources allocated by the dead subagent (possibly none). If any extensible subagent closes unexpectedly then all subagents with registered extensions will receive an agentx-IndexInvalid-PDU specifying the id of the dead extensible subagent. The subagents should immediately unregister any regions which depended on the dead extensible subagent. In the situation where subagent A is not present, subagent B's index reservation request immediately fails. Subagent B has the option of registering a MIB region using a self-made index or waiting until subagent A comes along before registering it's MIB region. In the situation where subagent A is present but does not support extending table T, the master agent responds to subagent B's request with error TABLE_NOT_EXTENSIBLE and subagent B is hosed until subagent A unregisters.   Delivery-Date: Mon, 18 Nov 1996 06:25:03 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id GAA26360 for X-agentx; Mon, 18 Nov 1996 06:25:02 -0800 (PST) Received: from relay1.UU.NET (relay1.UU.NET [192.48.96.5]) by fv.com (8.7.4/8.7.3) with ESMTP id GAA26322 for ; Mon, 18 Nov 1996 06:25:00 -0800 (PST) Received: from rocky.summa4.com by relay1.UU.NET with SMTP (peer crosschecked as: rocky.summa4.com [206.67.6.1]) id QQbqjh21173; Mon, 18 Nov 1996 09:24:54 -0500 (EST) Received: from sherman.summa4.com ([192.9.201.6]) by rocky.summa4.com via smtpd (for relay1.UU.NET [192.48.96.5]) with SMTP; 18 Nov 1996 14:23:13 UT Received: from summa4.summa4.com (summa4-b.summa4.com [192.9.201.50]) by Summa4.COM (8.7.6/8.7.1) with ESMTP id JAA14395 for ; Mon, 18 Nov 1996 09:23:13 -0500 (EST) Received: from birch.summa4.com (birch.summa4.com [192.9.201.147]) by summa4.summa4.com (8.7.6/8.7.1) with SMTP id JAA06002 for ; Mon, 18 Nov 1996 09:23:12 -0500 (EST) Received: from birch (localhost) by birch.summa4.com (4.1/SMI-4.1) id AA02607; Mon, 18 Nov 96 09:23:10 EST Sender: keeney@Summa4.COM Message-Id: <3290714D.167EB0E7@summa4.com> Date: Mon, 18 Nov 1996 09:23:09 -0500 From: David Keeney X-Mailer: Mozilla 3.0 (X11; I; SunOS 4.1.4 sun4c) Mime-Version: 1.0 To: agentx@fv.com Subject: Re: Has the new draft supposed to be out this month out? References: <3290FE40@msgate.future.futsoft.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit The Draft Revision 00.05 Dated Nov 5, has been posted at http://www.scguild.com/agentx David Keeney Software Contractors' Guild ======================== ravendrag wrote: > > Hi > > Has the new draft supposed to be out this month released? Please give me the > URL/reference for the draft standard. > > regards > ravendra > > ---------------- > This e-mail message was sent to all subscribers to the > agentx mailing list. > > To unsubscribe from this mailing list, please send mail to: > agentx-request@fv.com > with > Subject: unsubscribe your.address@your.domain > > (NOTE: Please do not reply to this message to unsubscribe. You must send > your request to agentx-request@fv.com Thank you.)   Delivery-Date: Mon, 18 Nov 1996 08:34:45 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id IAA07123 for X-agentx; Mon, 18 Nov 1996 08:34:45 -0800 (PST) Received: from igw3.watson.ibm.com (igw3.watson.ibm.com [129.34.139.18]) by fv.com (8.7.4/8.7.3) with ESMTP id IAA07120 for ; Mon, 18 Nov 1996 08:34:43 -0800 (PST) Received: from mailhub1.watson.ibm.com (mailhub1.watson.ibm.com [9.2.249.31]) by igw3.watson.ibm.com (8.7.6/8.7.1) with ESMTP id LAA10408; Mon, 18 Nov 1996 11:30:47 -0500 Received: from hawpub.watson.ibm.com (hawpub.watson.ibm.com [9.2.90.19]) by mailhub1.watson.ibm.com (8.8.2/11-10-96) with SMTP id LAA603113; Mon, 18 Nov 1996 11:30:26 -0500 Received: by hawpub.watson.ibm.com (AIX 3.2/UCB 5.64/6/25/96) id AA32940; Mon, 18 Nov 1996 11:30:25 -0500 From: Uri Blumenthal Message-Id: <9611181630.AA32940@hawpub.watson.ibm.com> Subject: Re: default subagent timeout To: donryan@microsoft.com (Don Ryan) Date: Mon, 18 Nov 1996 11:30:25 -0500 (EST) Cc: agentx@fv.com In-Reply-To: from "Don Ryan" at Nov 18, 96 02:52:56 am Reply-To: uri@watson.ibm.com X-Mailer: ELM [version 2.4 PL25] Content-Type: text Don Ryan says: > if the default subagent timeout cannot be set by an administrator then > why expose it? So that an admin can know what the default is? > why can't the subagent apply it's default value to each > region when it is registered and save the master agent the hassle of > having maintain this value? Master agent might not care what the default is - but an admin might need to know it in order to decide whether to leave it alone? -- Regards, Uri uri@watson.ibm.com -=-=-=-=-=-=-   Delivery-Date: Mon, 18 Nov 1996 11:02:44 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id LAA21485 for X-agentx; Mon, 18 Nov 1996 11:02:43 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id LAA21482 for ; Mon, 18 Nov 1996 11:02:43 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id OAA16013 for ; Mon, 18 Nov 1996 14:04:09 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma015996; Mon, 18 Nov 96 11:03:41 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id LAA27587 for ; Mon, 18 Nov 1996 11:03:44 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id OAA15986 for ; Mon, 18 Nov 1996 14:03:39 -0500 (EST) Received: from mail1.microsoft.com(131.107.3.41) by gauntlet.fv.com via smap (3.2) id xma015980; Mon, 18 Nov 96 11:03:24 -0800 Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD53E.F5C4E1B0@INET-01-IMC.microsoft.com>; Mon, 18 Nov 1996 10:55:07 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" Subject: processing searchranges in order Date: Mon, 18 Nov 1996 10:56:35 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 7 TEXT In section 7.2.2, why is it necessary to specify that each SearchRange must be processed in order? A shim subagent may be dispatching requests to other non-agentx subagents in the same manner in which they were dispatched to him; i.e., in a bulk request. What does it matter if SR2 & SR3 both have problems and the shim returns errorIndex=SR3? I would assume the problem with SR3 would be cleaned up and the new request will fail with SR2 which will eventually be cleaned up.   Delivery-Date: Wed, 20 Nov 1996 10:01:02 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id KAA06263 for X-agentx; Wed, 20 Nov 1996 10:01:02 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id KAA06254 for ; Wed, 20 Nov 1996 10:01:01 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA04729 for ; Wed, 20 Nov 1996 13:02:23 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma004716; Wed, 20 Nov 96 10:01:54 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id KAA21280 for ; Wed, 20 Nov 1996 10:02:01 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA04713 for ; Wed, 20 Nov 1996 13:01:53 -0500 (EST) Received: from mail11.digital.com(192.208.46.10) by gauntlet.fv.com via smap (3.2) id xma004707; Wed, 20 Nov 96 10:01:45 -0800 Received: from flume.zk3.dec.com by mail11.digital.com (8.7.5/UNX 1.5/1.0/WV) id MAA28123; Wed, 20 Nov 1996 12:54:09 -0500 (EST) Received: from bernie.zk3.dec.com by flume.zk3.dec.com; (5.65v3.2/1.1.8.2/16Jan95-0946AM) id AA04861; Wed, 20 Nov 1996 12:54:08 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09461; Wed, 20 Nov 1996 12:57:40 -0500 Message-Id: <9611201757.AA09461@bernie.zk3.dec.com> To: agentx@fv.com Subject: RE: Discussion of AgentX protocol draft ver 00.05 Date: Wed, 20 Nov 96 12:57:39 -0500 From: Mike Daniele X-Mts: smtp >From: Don Ryan >To: "'dfrancis@stratacom.com'" >Cc: "'agentx@fv.com'" >Subject: RE: Discussion of AgentX protocol draft ver 00.05 >Date: Fri, 15 Nov 1996 14:36:34 -0800 >X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 >X-Suppressed-Encoding: 17 TEXT >I agree with the removal of the agent capabilities (sysORTable) OID from >the agentx-Open-PDU. I am wondering, though, what happens in the case >of overlapping registrations that have different capabilities. The >subagent is the only entity which can map the sysORTable OID to one or >more of it's registered MIB regions but it has no concept of whether or >not all or part of it's registered MIB region is hidden by another >subagent at a higher priority. I think that given the static nature of MIB specifications and sysORIDs, and the dynamic nature of AgentX registration (overlap), there is no way to avoid the problem you describe. > Instead of agentx-AddAgentCaps and >agentx-RemoveAgentCaps, should we have just a agentx-GetAgentCaps-PDU >which takes a context and MIB range as input and returns a >agentx-Response-PDU with the OID of the corresponding capabilities >statement? Are you saying the OID returned by the subagent is a function of the current AgentX registry? Let's say my subagent implements mib-2, and I produce a MIB spec with an agent-capabilities statement describing my implementation, and identifying it with oid o1. On some particular system, some other subagent registers `ip', which is more fully qualified and hence will be dispatched to instead of me (assuming I registered 'mib-2'). Does the master agent send me an agentx-GetAgentCaps-PDU with a range of mib-2 up to 'ip'? And if so, am I supposed to return an oid different than o1? If I return o1, the end result is not different than if the mechanism in v5 is applied. If I return a different oid, it's not useful because there is no MIB spec that defined that oid in an agent-capabilities statement. Or am I missing the point? Mike   Delivery-Date: Wed, 20 Nov 1996 10:14:43 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id KAA07627 for X-agentx; Wed, 20 Nov 1996 10:14:42 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id KAA07624 for ; Wed, 20 Nov 1996 10:14:42 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA06036 for ; Wed, 20 Nov 1996 13:16:04 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma006011; Wed, 20 Nov 96 10:15:35 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id KAA22205 for ; Wed, 20 Nov 1996 10:15:42 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA06006 for ; Wed, 20 Nov 1996 13:15:34 -0500 (EST) Received: from mail13.digital.com(192.208.46.30) by gauntlet.fv.com via smap (3.2) id xma005997; Wed, 20 Nov 96 10:15:28 -0800 Received: from flume.zk3.dec.com by mail13.digital.com (8.7.5/UNX 1.5/1.0/WV) id NAA27300; Wed, 20 Nov 1996 13:07:29 -0500 (EST) Received: from bernie.zk3.dec.com by flume.zk3.dec.com; (5.65v3.2/1.1.8.2/16Jan95-0946AM) id AA07171; Wed, 20 Nov 1996 13:07:28 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09470; Wed, 20 Nov 1996 13:11:03 -0500 Message-Id: <9611201811.AA09470@bernie.zk3.dec.com> To: agentx@fv.com Subject: re: processing searchranges in order Date: Wed, 20 Nov 96 13:11:03 -0500 From: Mike Daniele X-Mts: smtp >From: Don Ryan >In section 7.2.2, why is it necessary to specify that each SearchRange >must be processed in order? It is not necessary. Thanks for pointing this out. Mike   Delivery-Date: Wed, 20 Nov 1996 11:15:12 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id LAA12694 for X-agentx; Wed, 20 Nov 1996 11:15:12 -0800 (PST) Received: from mail12.digital.com (mail12.digital.com [192.208.46.20]) by fv.com (8.7.4/8.7.3) with ESMTP id LAA12691 for ; Wed, 20 Nov 1996 11:15:10 -0800 (PST) Received: from hunch.zk3.dec.com by mail12.digital.com (8.7.5/UNX 1.5/1.0/WV) id OAA27608; Wed, 20 Nov 1996 14:00:58 -0500 (EST) Received: from bernie.zk3.dec.com by hunch.zk3.dec.com; (5.65v3.2/1.1.8.2/11Mar96-0342PM) id AA06039; Wed, 20 Nov 1996 14:00:57 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09544; Wed, 20 Nov 1996 14:04:32 -0500 Message-Id: <9611201904.AA09544@bernie.zk3.dec.com> To: agentx@fv.com Subject: agentx-IndexReserve-PDU Date: Wed, 20 Nov 96 14:04:30 -0500 From: Mike Daniele X-Mts: smtp >From: Don Ryan >I do not see how a master agent can be "MIB ignorant" yet know how to >allocate new (or any) instances of an index. It keeps track of a set of oids, and for each oid a set of integers. What MIB knowldedge is required to do this? >The comments for this PDU >mentions "if v.type is not supported by the master agent" which does not >seem very extensible to me. How about: It's extensible to the extent that if you want to support indexes of other types in your master agent, you may do so. AgentX requires you to support integers, and to return the appropriate error for other types if you don't support them. I'm not sure what you're getting at. >a.) subagent A registers MIB region M containing table T and sets >FLAG_ACCEPT_EXTENSIONS to TRUE. >b.) subagent B asks master agent for an index in table T ... One of our requirements is that index *reservation* be decoupled from MIB *registration*. The master agent does not consult the state of index reservations when processing a registration request. It also does not consult the current registry when processing an index-reservation request. The idea is that subagents will request suitable index values for oids that need them, THEN register whatever region makes sense, probably using an index value they reserved. It's possible that the reservation will fail as a duplicate (because some other subagent registered without first reserving an index). In which case the subagent has to try another index value. The idea was to provide a mechanism that permits good citizen subagents to share tables efficiently, but that still works when the Fred Router company agent that always registers interface 2 is present. Mike   Delivery-Date: Wed, 20 Nov 1996 11:38:26 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id LAA14850 for X-agentx; Wed, 20 Nov 1996 11:38:25 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id LAA14845 for ; Wed, 20 Nov 1996 11:38:25 -0800 (PST) From: maria@xedia.com Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id OAA11410 for ; Wed, 20 Nov 1996 14:39:45 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma011391; Wed, 20 Nov 96 11:39:16 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id LAA29979 for ; Wed, 20 Nov 1996 11:39:23 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id OAA11384 for ; Wed, 20 Nov 1996 14:39:16 -0500 (EST) Received: from charity.harvard.net(206.137.222.16) by gauntlet.fv.com via smap (3.2) id xma011377; Wed, 20 Nov 96 11:39:01 -0800 Received: from xedia.com ([198.202.232.199]) by charity.harvard.net (8.8.3/8.7.3) with SMTP id OAA21196; Wed, 20 Nov 1996 14:42:56 -0500 (EST) Received: from (espanola) by xedia.com (4.1/SMI-4.1) id AA02162; Wed, 20 Nov 96 14:32:46 EST Received: by (5.x/SMI-SVR4) id AA10099; Wed, 20 Nov 1996 14:37:45 -0500 Date: Wed, 20 Nov 1996 14:37:45 -0500 Message-Id: <9611201937.AA10099@> To: Mike Daniele Cc: agentx@fv.com Subject: Re: agentx-IndexReserve-PDU References: <9611201904.AA09544@bernie.zk3.dec.com> In replying to a question from Don Ryan, Mike said: > One of our requirements is that index *reservation* be decoupled > from MIB *registration*. The master agent does not consult the > state of index reservations when processing a registration > request. It also does not consult the current registry when > processing an index-reservation request. ... > The idea is that subagents will request suitable index values > for oids that need them, THEN register whatever region makes > sense, probably using an index value they reserved. > It's possible that the reservation will fail as a duplicate > (because some other subagent registered without first reserving > an index). In which case the subagent has to try another index > value. I think you mean "It's possible that the *registration* will fail as a duplicate..." (We should have called it "index allocation" or something like that.) > The idea was to provide a mechanism that permits good citizen > subagents to share tables efficiently, but that still works when > the Fred Router company agent that always registers interface 2 > is present. Yes, for example, we purchased a MIB-2 subagent that always registered ifIndex.1 (for the port on the management card) then we had our own subagents that handled "I/O cards" that used a similar index reservation scheme to number the additional interfaces. Maria maria@xedia.com   Delivery-Date: Wed, 20 Nov 1996 12:07:49 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id MAA17333 for X-agentx; Wed, 20 Nov 1996 12:07:49 -0800 (PST) Received: from mail11.digital.com (mail11.digital.com [192.208.46.10]) by fv.com (8.7.4/8.7.3) with ESMTP id MAA17330 for ; Wed, 20 Nov 1996 12:07:48 -0800 (PST) Received: from flume.zk3.dec.com by mail11.digital.com (8.7.5/UNX 1.5/1.0/WV) id OAA29489; Wed, 20 Nov 1996 14:57:47 -0500 (EST) Received: from bernie.zk3.dec.com by flume.zk3.dec.com; (5.65v3.2/1.1.8.2/16Jan95-0946AM) id AA11161; Wed, 20 Nov 1996 14:57:54 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09507; Wed, 20 Nov 1996 15:01:23 -0500 Message-Id: <9611202001.AA09507@bernie.zk3.dec.com> To: agentx@fv.com Subject: Re: agentx-IndexReserve-PDU In-Reply-To: Your message of "Wed, 20 Nov 96 14:37:45 EST." <9611201937.AA10099@> Date: Wed, 20 Nov 96 15:01:22 -0500 From: Mike Daniele X-Mts: smtp >From: > > It's possible that the reservation will fail as a duplicate > > (because some other subagent registered without first reserving > > an index). In which case the subagent has to try another index > > value. >I think you mean "It's possible that the *registration* will fail as a >duplicate..." (We should have called it "index allocation" or >something like that.) Correct, thanks. > > The idea was to provide a mechanism that permits good citizen > > subagents to share tables efficiently, but that still works when > > the Fred Router company agent that always registers interface 2 > > is present. >Yes, for example, we purchased a MIB-2 subagent that always registered >ifIndex.1 i messed up the interface index too! :-) Thanks for the clarifying example, Mike   Delivery-Date: Wed, 20 Nov 1996 12:59:49 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id MAA21976 for X-agentx; Wed, 20 Nov 1996 12:59:48 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id MAA21973 for ; Wed, 20 Nov 1996 12:59:48 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id QAA16211 for ; Wed, 20 Nov 1996 16:01:09 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma016204; Wed, 20 Nov 96 13:00:40 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id NAA06343 for ; Wed, 20 Nov 1996 13:00:46 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id QAA16200 for ; Wed, 20 Nov 1996 16:00:39 -0500 (EST) Received: from mail1.microsoft.com(131.107.3.41) by gauntlet.fv.com via smap (3.2) id xma016198; Wed, 20 Nov 96 13:00:38 -0800 Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD6E1.54C31F80@INET-01-IMC.microsoft.com>; Wed, 20 Nov 1996 12:49:56 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" , "'Mike Daniele'" Subject: RE: completely hidden subagents Date: Wed, 20 Nov 1996 12:50:51 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 74 TEXT Hi Mike, Actually, my main goal was trying to find a way to remove (or hide) a subagent's capabilities OID in the sysORTable if all (not some) of the subagent's associated MIB regions are hidden by one or more subagents at higher priority. Perhaps this is this not something to be concerned about. What is your opinion? The subagent should definitely not return different OIDs depending upon whether or not certain regions are hidden. I was suggesting that the master agent not return the capabilities OID of completely hidden subagents and perhaps the master agent should therefore ask for the subagent capabilities when and if he needs them as opposed to being told. The inclusion of the MIB region in the GetCaps-PDU was a mistake. It just seemed odd to me that the sysORTable was not being filled in on demand. >---------- >From: Mike Daniele[SMTP:daniele@zk3.dec.com] >Sent: Wednesday, November 20, 1996 9:57 AM >To: agentx@fv.com >Subject: RE: Discussion of AgentX protocol draft ver 00.05 > > >>From: Don Ryan >>To: "'dfrancis@stratacom.com'" >>Cc: "'agentx@fv.com'" >>Subject: RE: Discussion of AgentX protocol draft ver 00.05 >>Date: Fri, 15 Nov 1996 14:36:34 -0800 >>X-Mailer: Microsoft Exchange Server Internet Mail Connector Version >>4.0.994.63 >>X-Suppressed-Encoding: 17 TEXT > >>I agree with the removal of the agent capabilities (sysORTable) OID from >>the agentx-Open-PDU. I am wondering, though, what happens in the case >>of overlapping registrations that have different capabilities. The >>subagent is the only entity which can map the sysORTable OID to one or >>more of it's registered MIB regions but it has no concept of whether or >>not all or part of it's registered MIB region is hidden by another >>subagent at a higher priority. > >I think that given the static nature of MIB specifications and sysORIDs, >and the dynamic nature of AgentX registration (overlap), there is no >way to avoid the problem you describe. > >> Instead of agentx-AddAgentCaps and >>agentx-RemoveAgentCaps, should we have just a agentx-GetAgentCaps-PDU >>which takes a context and MIB range as input and returns a >>agentx-Response-PDU with the OID of the corresponding capabilities >>statement? > >Are you saying the OID returned by the subagent is a function >of the current AgentX registry? > >Let's say my subagent implements mib-2, and I produce a MIB spec >with an agent-capabilities statement describing my implementation, >and identifying it with oid o1. > >On some particular system, some other subagent registers `ip', which is >more fully qualified and hence will be dispatched to instead of me >(assuming I registered 'mib-2'). > >Does the master agent send me an agentx-GetAgentCaps-PDU with a range >of mib-2 up to 'ip'? And if so, am I supposed to return an oid different >than o1? > >If I return o1, the end result is not different than if the mechanism >in v5 is applied. > >If I return a different oid, it's not useful because there is no MIB >spec that defined that oid in an agent-capabilities statement. > >Or am I missing the point? > >Mike >   Delivery-Date: Wed, 20 Nov 1996 13:52:59 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id NAA26311 for X-agentx; Wed, 20 Nov 1996 13:52:59 -0800 (PST) Received: from mail12.digital.com (mail12.digital.com [192.208.46.20]) by fv.com (8.7.4/8.7.3) with ESMTP id NAA26308 for ; Wed, 20 Nov 1996 13:52:58 -0800 (PST) Received: from flume.zk3.dec.com by mail12.digital.com (8.7.5/UNX 1.5/1.0/WV) id QAA17835; Wed, 20 Nov 1996 16:37:50 -0500 (EST) Received: from bernie.zk3.dec.com by flume.zk3.dec.com; (5.65v3.2/1.1.8.2/16Jan95-0946AM) id AA10030; Wed, 20 Nov 1996 16:37:59 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09663; Wed, 20 Nov 1996 16:41:21 -0500 Message-Id: <9611202141.AA09663@bernie.zk3.dec.com> To: agentx@fv.com Cc: dbh@ctron.com Subject: RE: completely hidden subagents Date: Wed, 20 Nov 96 16:41:20 -0500 From: Mike Daniele X-Mts: smtp >From: Don Ryan >Actually, my main goal was trying to find a way to remove (or hide) a >subagent's capabilities OID in the sysORTable if all (not some) of the >subagent's associated MIB regions are hidden by one or more subagents at >higher priority. Perhaps this is this not something to be concerned >about. What is your opinion? My opinion may be colored by the fact that I personally have never seen a NMS or application actually *use* agent capabilities. (The one I have some interaction with is Netview.) I think AgentX should provide a mechanism for subagents to notify the master of their capabilities. It must be optional and should be driven by the subagents, since many subagents will not support agent-caps. The populated sysORTable should represent capabilities (some possibly latent), *not* a snapshot of the current registry reflecting what subagent would currently be dispatched to for any given oid. If a NMS can read the sysORTable, interpret those values, detect there is an overlap of capabilities (and hence may be a registration overlap), and cares (pretty unlikely in my book but I live under a rock), then it can look in the AgentX MIB to understand the registry. So we should keep this functionality in AgentX as simple as possible while still providing a general mechanism that works with our notion of subagents registering within contexts. Well, you asked... :-) Mike   Delivery-Date: Wed, 20 Nov 1996 15:35:45 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id PAA04772 for X-agentx; Wed, 20 Nov 1996 15:35:45 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id PAA04769 for ; Wed, 20 Nov 1996 15:35:44 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id SAA28365 for ; Wed, 20 Nov 1996 18:37:04 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma028309; Wed, 20 Nov 96 15:36:35 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id PAA20075 for ; Wed, 20 Nov 1996 15:36:43 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id SAA28288 for ; Wed, 20 Nov 1996 18:36:34 -0500 (EST) Received: from mail1.microsoft.com(131.107.3.41) by gauntlet.fv.com via smap (3.2) id xma028279; Wed, 20 Nov 96 15:36:33 -0800 Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD6F7.9ABFAE20@INET-01-IMC.microsoft.com>; Wed, 20 Nov 1996 15:29:22 -0800 Message-ID: From: Don Ryan To: "'agentx@fv.com'" , "'Mike Daniele'" Subject: RE: agentx-IndexReserve-PDU Date: Wed, 20 Nov 1996 15:30:18 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 113 TEXT Hi Mike, There is implicit MIB knowledge in the agentx-IndexReserve-PDU. The PDU only enables sharing of tables with a single integer index whose value has no other constraints other than being unique. The master agent can therefore pull on integer out of the air and hand it back to the requesting subagent without problems. I fail to see how this scheme will work with tables with more than one index value or with tables with non-integer index values or with tables with non-random integer index values. In order for any of these other tables to work with this PDU, the master agent will need to have a priori knowledge on how to allocate a new index or any index for the table in question. I would suggest that the master be the arbitrator and perhaps even the repository for shared state but not be responsible for actually allocating the index value. Removing any implicit or explicit MIB knowledge from the master agent is more important than to me than completely decoupling MIB registration from index reservation. In fact, in your scheme how do you handle the case where it is the MIB2 subagent who is lazy and does not bother to reserve any indices. Fred Router comes along, successfully registers the ifIndex 2 and one of the MIB2 subagent's interfaces gets hidden. In my scheme, the lazy MIB2 subagent does not (by default) enable the extensibility flag and the master agent would reject Fred Router's registration. In my example below, you could have subagent A send an index reservation PDU before registration which failed saying nobody else was presently interested in that table in which case he would allocate the index values as he saw fit and then add these to some shared state stored in the master agent. When subagent A was done reserving indices he would register the MIB region(s) he was willing to support. This works like your scheme expect that the subagent knows how to allocate the index and therefore it can be of any type and can consist of any number of components. If subagent B comes along and tries to register without reserving an index then detection will work the same as in your scheme. If subagent B tries to reserve an index subagent before registering (recommended) the master agent would then: if (fNewIndex || fAnyIndex) { for (every other subagent contributing to table) { fOk=ReserveIndex(subagentN,&reservedIndex,fNewIndex,fAnyIndex) if fOk then return reservedIndex } return ERROR_GET_YOUR_OWN_INDEX } else { check reserved indices table to see if already taken if taken return error ERROR_INDEX_RESERVED else add to table and return success } Regards, Don >---------- >From: Mike Daniele[SMTP:daniele@zk3.dec.com] >Sent: Wednesday, November 20, 1996 11:04 AM >To: agentx@fv.com >Subject: agentx-IndexReserve-PDU > >>From: Don Ryan > >>I do not see how a master agent can be "MIB ignorant" yet know how to >>allocate new (or any) instances of an index. > >It keeps track of a set of oids, and for each oid a set of integers. >What MIB knowldedge is required to do this? > >>The comments for this PDU >>mentions "if v.type is not supported by the master agent" which does not >>seem very extensible to me. How about: > >It's extensible to the extent that if you want to support indexes of other >types in your master agent, you may do so. AgentX requires you to >support integers, and to return the appropriate error for other types if >you don't support them. > >I'm not sure what you're getting at. > >>a.) subagent A registers MIB region M containing table T and sets >>FLAG_ACCEPT_EXTENSIONS to TRUE. >>b.) subagent B asks master agent for an index in table T > >... > >One of our requirements is that index *reservation* be decoupled from >MIB *registration*. The master agent does not consult the state of index >reservations when processing a registration request. It also does not >consult the current registry when processing an index-reservation request. > >The idea is that subagents will request suitable index values for oids >that need them, THEN register whatever region makes sense, probably using >an index value they reserved. > >It's possible that the reservation will fail as a duplicate >(because some other subagent registered without first reserving >an index). In which case the subagent has to try another index value. > >The idea was to provide a mechanism that permits good citizen subagents >to share tables efficiently, but that still works when the Fred Router >company agent that always registers interface 2 is present. > >Mike > >---------------- >This e-mail message was sent to all subscribers to the >agentx mailing list. > >To unsubscribe from this mailing list, please send mail to: > agentx-request@fv.com >with > Subject: unsubscribe your.address@your.domain > >(NOTE: Please do not reply to this message to unsubscribe. You must send >your request to agentx-request@fv.com Thank you.) >   Delivery-Date: Thu, 21 Nov 1996 07:47:19 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id HAA16898 for X-agentx; Thu, 21 Nov 1996 07:47:19 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id HAA16895 for ; Thu, 21 Nov 1996 07:47:19 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id KAA10951 for ; Thu, 21 Nov 1996 10:48:37 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma010943; Thu, 21 Nov 96 07:48:08 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id HAA22438 for ; Thu, 21 Nov 1996 07:48:16 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id KAA10940 for ; Thu, 21 Nov 1996 10:48:07 -0500 (EST) Received: from mail12.digital.com(192.208.46.20) by gauntlet.fv.com via smap (3.2) id xma010937; Thu, 21 Nov 96 07:47:40 -0800 Received: from hunch.zk3.dec.com by mail12.digital.com (8.7.5/UNX 1.5/1.0/WV) id KAA00633; Thu, 21 Nov 1996 10:31:34 -0500 (EST) Received: from bernie.zk3.dec.com by hunch.zk3.dec.com; (5.65v3.2/1.1.8.2/11Mar96-0342PM) id AA08953; Thu, 21 Nov 1996 10:31:33 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA09899; Thu, 21 Nov 1996 10:35:08 -0500 Message-Id: <9611211535.AA09899@bernie.zk3.dec.com> To: agentx@fv.com Subject: RE: agentx-IndexReserve-PDU Date: Thu, 21 Nov 96 10:35:08 -0500 From: Mike Daniele X-Mts: smtp Hi Don, >From: Don Ryan >Hi Mike, >There is implicit MIB knowledge in the agentx-IndexReserve-PDU. I don't agree, but I think we're stumbling over different assumptions, see below. >The PDU only enables sharing of tables with a single integer index whose value >has no other constraints other than being unique. The master agent can >therefore pull on integer out of the air and hand it back to the >requesting subagent without problems. So you agree that this much anyway can be done without "MIB knowledge"? >I fail to see how this scheme >will work with tables with more than one index value You reserve values for each index (if necessary). >...or with tables with non-integer index values You ask your master agent provider to support the necessary data types. AgentX is extensible enough to handle it :-) If the community thinks there are other types that will commonly need to be supported, let's add em to the spec. >...or with tables with non-random integer index values. Can you be more explicit here? By non-random do you mean "that have semantic meaning" or something else? The general problem we're addressing is that of sharing tables whose index(es) are arbitrary integers. There are lots and lots of such tables defined in the internet standard mib, and all over, so we think it's worthwhile. Index values for these tables are frequently required to be unique over the life of the agent, so we've added that feature as well (NEVER_USED bit, etc). I believe that what we've defined now permits us to support sharing of a large percentage (90-something%) of tables that need to be shared, without requiring any knowledge of any mib in the master agent. Would you agree to this much? Tables whose index values have semantic meaning (are a process id, are a tcp connection, etc) do not in general lend themselves well to this model. I think this is essentially your argument? Is this what you refer to in >In order for any of these other tables to work with this PDU, >the master agent will need to have a priori knowledge on how to allocate >a new index or any index for the table in question. In general, I *think* it's fairly uncommon for such tables to be distributed between subagents. In those cases where it happens, some things to consider are: a) use lex ordering to your benefit. instead of trying to register each row (full instances), register a larger chunk. For instance, if a subagent reserved ifIndex 7 and registered ifTable.[1-22].7 successfully, it could register ipNetToMediaTable.[1-4].7 instead of rows in that table. Note that this also prevents the subagent from having to reserve values of ipNetToMediaNetAddress. We've discussed tcpConnTable on this list as another example of registering mib chunks instead of rows (or the entire table). b) the subagent *can* convey its MIB knowledge to the master, by requesting a specific value be reserved. c) subagents that really need to share tables that can't be reasonably "provisioned" this way can use some other mechanism. >I would suggest >that the master be the arbitrator and perhaps even the repository for >shared state but not be responsible for actually allocating the index >value. Removing any implicit or explicit MIB knowledge from the master >agent is more important than to me than completely decoupling MIB >registration from index reservation. In fact, in your scheme how do you >handle the case where it is the MIB2 subagent who is lazy and does not >bother to reserve any indices. Fred Router comes along, successfully >registers the ifIndex 2 and one of the MIB2 subagent's interfaces gets >hidden. The consensus is that that is the correct behavior! More fully qualified registrations "win", and registrations are not processed wrt currently reserved indexes. Your idea seems to require all subagents to provide index reservation capabilities, and also seems to have a number of dependencies on how subagents interact. I don't think it's a good design that permits, say, subagent A to register mib-2 with the EXTENSION-FLAG off, and thereby lock out any other subagent from registering anything within mib-2. There is strong consensus that we have "open" registrations, any sub can register anything any time. - our only restrictions are no duplicates (defined as per spec). - our only dispatching rules are "most qualified wins, if tied highest priority wins" - subagents require no knowldge of or presence of other subagents (the consensus is less strong around "duplicates") "helpful" index reservation - act as hints for what to register - a service provided by AgentX master, so subagent implementations don't have to - do NOT effect registrations Regards, Mike   Delivery-Date: Thu, 21 Nov 1996 14:13:20 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id OAA17316 for X-agentx; Thu, 21 Nov 1996 14:13:19 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id OAA17313 for ; Thu, 21 Nov 1996 14:13:19 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA04544 for ; Thu, 21 Nov 1996 17:14:38 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma004513; Thu, 21 Nov 96 14:14:08 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id OAA21238 for ; Thu, 21 Nov 1996 14:14:16 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA04506 for ; Thu, 21 Nov 1996 17:14:07 -0500 (EST) Received: from mail1.microsoft.com(131.107.3.41) by gauntlet.fv.com via smap (3.2) id xma004498; Thu, 21 Nov 96 14:13:52 -0800 Received: by INET-01-IMC.microsoft.com with SMTP (Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63) id <01BBD7B5.11BEA5E0@INET-01-IMC.microsoft.com>; Thu, 21 Nov 1996 14:05:36 -0800 Message-ID: From: Don Ryan To: "'Mike Daniele'" Cc: "'agentx@fv.com'" Subject: RE: agentx-IndexReserve-PDU Date: Thu, 21 Nov 1996 14:06:43 -0800 X-Mailer: Microsoft Exchange Server Internet Mail Connector Version 4.0.994.63 Encoding: 35 TEXT Hi Mike, Thanks for clarifying your goals and assumptions. I think it would be really helpful to add some of this information to the draft. I think it would also be useful if you could clarify under want circumstances you are recommending that a "well-behaved" subagent reserve the indices used in their various tables. If a given table is indexed by an arbitrary integer, should a "well-behaved" subagent always reserve all of the table's indices with the master agent? Regards, Don >---------- >From: Mike Daniele[SMTP:daniele@zk3.dec.com] >Sent: Thursday, November 21, 1996 7:35 AM >To: agentx@fv.com >Subject: RE: agentx-IndexReserve-PDU > >The general problem we're addressing is that of sharing tables whose >index(es) are >arbitrary integers. > > >I believe that what we've defined now permits us to support sharing of a >large >percentage (90-something%) of tables that need to be shared > >   Delivery-Date: Fri, 22 Nov 1996 10:17:49 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id KAA19103 for X-agentx; Fri, 22 Nov 1996 10:17:44 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id KAA19098 for ; Fri, 22 Nov 1996 10:17:43 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA08574 for ; Fri, 22 Nov 1996 13:19:00 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma008555; Fri, 22 Nov 96 10:18:32 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id KAA09501 for ; Fri, 22 Nov 1996 10:18:40 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id NAA08533 for ; Fri, 22 Nov 1996 13:18:30 -0500 (EST) Received: from stratacom.strata.com(204.179.0.2) by gauntlet.fv.com via smap (3.2) id xma008498; Fri, 22 Nov 96 10:18:20 -0800 Received: from Strata.COM (kiwi.strata.com) by stratacom.strata.com (4.1/SMI-4.1/Gatekeeper.Strata.Com-950201) id AA20998; Fri, 22 Nov 96 10:16:53 PST Received: from santa.strata.com (santa-le1) by Strata.COM (4.1/SMI-4.1/StrataCom-GCA-Kiwi-931007-1) id AA24458; Fri, 22 Nov 96 10:12:29 PST Received: from marvell.strata.com by santa.strata.com (4.1/SMI-4.1/StrataCom-GCA-SunClient-LOCAL-931101) id AA19334; Fri, 22 Nov 96 10:16:51 PST Date: Fri, 22 Nov 96 10:16:51 PST From: dfrancis@stratacom.com (Dale Francisco) Message-Id: <9611221816.AA19334@santa.strata.com> To: agentx@fv.com Subject: Re: Latest draft of extensible SNMP agent protocol available Cc: Peter.Polkinghorne@brunel.ac.uk Here are some comments from someone who saw the recent announcement of the AgentX draft on the snmpv2 list. It's nice to get some feedback on what's clear and what isn't from a knowledgeable person reading the draft for the first time. Dale ----- Begin Included Message ----- From Peter.Polkinghorne@brunel.ac.uk Fri Nov 22 07:58:18 1996 X-Mailer: exmh version 1.6.6 3/24/96 To: dfrancis@strata.com (Dale Francisco) Cc: Peter.Polkinghorne@brunel.ac.uk Subject: Re: Latest draft of extensible SNMP agent protocol available Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 22 Nov 1996 15:57:06 +0000 From: Peter Polkinghorne Content-Length: 1903 Firstly thank you for drawing the SNMPv2 mailing list's attention to this draft. However 2 days is not long to read and absorb a 67 page document, even when you have the appropriate background. My background is that have read other SNMP RFCs, writen a few SNMP agents and read the relevant Simple Times on extensible snmp agents. Comments (based on reading draft 5): p.26 6.2.5 The agentx-Get-PDU: not blindingly obvious that the search range list consists of multiple start-end pairs - I am assuming this is what the trailing elipsis means. This comment applies to the other implied lists in the PDU descriptions. Apologies if this is conventional terminology, but to someone reading just the draft it is not obvious. 7.1.1 Is there a procedure for Master Agent to detect dead subagents (and indeed vice versa)? OK see mentioned in 7.1.9, but for master only. 7.1.2 Should a subagent that reserves an index more than once be given an error response? This is my understanding of what the section proposes. 7.1.10 Should not the master supplied SysUpTime.0 be context specific? (As in 7.1.4 5) ) 7.2.1.2 What happens when a get-next request starts in one subagent's range, but the next instance is actually in another subagent's range? e.g. some one just get-nexting their way thru' the MIB. Not at all clear from this section. There seems to be missing what to do when the sub-agent does not have an instance, ie no looping contruct. This does not seem to be handled in 7.2.2.2 but is I see in 7.2.4.3 - may be forward ref would be helpful? 7.2.3 Why do the respponses not have a VarBindList? This prevents the set value X get back value Y1 or Y2 or ... paradigm. There seems to be nothing on sub-agent recovery from master agent failure. The lack of security is a worry. However does seem to reasonably clear and I look forward to its progression to a standard. ----- End Included Message -----   Delivery-Date: Fri, 22 Nov 1996 12:06:54 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id MAA28164 for X-agentx; Fri, 22 Nov 1996 12:06:53 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id MAA28161 for ; Fri, 22 Nov 1996 12:06:53 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id PAA16421 for ; Fri, 22 Nov 1996 15:08:09 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma016412; Fri, 22 Nov 96 12:07:40 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id MAA17093 for ; Fri, 22 Nov 1996 12:07:49 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id PAA16400 for ; Fri, 22 Nov 1996 15:07:39 -0500 (EST) Received: from mail11.digital.com(192.208.46.10) by gauntlet.fv.com via smap (3.2) id xma016392; Fri, 22 Nov 96 12:07:26 -0800 Received: from hunch.zk3.dec.com by mail11.digital.com (8.7.5/UNX 1.5/1.0/WV) id OAA12439; Fri, 22 Nov 1996 14:50:38 -0500 (EST) Received: from bernie.zk3.dec.com by hunch.zk3.dec.com; (5.65v3.2/1.1.8.2/11Mar96-0342PM) id AA18730; Fri, 22 Nov 1996 14:50:36 -0500 Received: from localhost by bernie.zk3.dec.com; (5.65/1.1.8.2/22Aug96-1117AM) id AA10596; Fri, 22 Nov 1996 14:54:11 -0500 Message-Id: <9611221954.AA10596@bernie.zk3.dec.com> To: agentx@fv.com Subject: Re: Latest draft of extensible SNMP agent protocol available In-Reply-To: Your message of "Fri, 22 Nov 96 10:16:51 PST." <9611221816.AA19334@santa.strata.com> Date: Fri, 22 Nov 96 14:54:11 -0500 From: Mike Daniele X-Mts: smtp >From Peter.Polkinghorne@brunel.ac.uk Fri Nov 22 07:58:18 1996 >p.26 6.2.5 The agentx-Get-PDU: not blindingly obvious that the search range >list consists of multiple start-end pairs - I am assuming this is what the >trailing elipsis means. >This comment applies to the other implied lists in the PDU descriptions. >Apologies if this is conventional terminology, but to someone reading just the >draft it is not obvious. I think that's a good point, we should probably list "search range 1", search range n", or something. And do this in all cases where there are multiple repeated items. >7.1.1 Is there a procedure for Master Agent to detect dead subagents (and >indeed vice versa)? OK see mentioned in 7.1.9, but for master only. I think we're pretty clear here with the Ping-PDU for the subagent to detect the master's status, and the master timing out and potentially closing the session. >7.1.2 Should a subagent that reserves an index more than once be given an >error response? This is my understanding of what the section proposes. Yes, that's what the section proposes. >7.1.10 Should not the master supplied SysUpTime.0 be context specific? (As in >7.1.4 5) Yes, that section should reference "the indicated context". >7.2.1.2 What happens when a get-next request starts in one subagent's range, >but the next instance is actually in another subagent's range? e.g. some one >just get-nexting their way thru' the MIB. Not at all clear from this section. > There seems to be missing what to do when the sub-agent does not have an >instance, ie no looping contruct. This does not seem to be handled in 7.2.2.2 >but is I see in 7.2.4.3 - may be forward ref would be helpful? Suggestions welcome... :-) >7.2.3 Why do the respponses not have a VarBindList? This prevents the set >value X get back value Y1 or Y2 or ... paradigm. I don't see this paradigm mentioned in section 4.2.5 of RFC 1905... Do folks think we need to do this? I know Bert won't :-) >There seems to be nothing on sub-agent recovery from master agent failure. Good point. About all we can say is the subagent needs to reestablish a session and reregister. >The lack of security is a worry. I assume most implementors have a handle on this, since there hasn't been any push to include security in AgentX (that I recall anyway). >However does seem to reasonably clear and I look forward to its progression to >a standard. Good news... Mike   Delivery-Date: Fri, 22 Nov 1996 13:46:20 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id NAA06552 for X-agentx; Fri, 22 Nov 1996 13:46:20 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id NAA06549 for ; Fri, 22 Nov 1996 13:46:19 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id QAA22249 for ; Fri, 22 Nov 1996 16:47:35 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma022229; Fri, 22 Nov 96 13:47:06 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id NAA23631 for ; Fri, 22 Nov 1996 13:47:16 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id QAA22224 for ; Fri, 22 Nov 1996 16:47:05 -0500 (EST) Received: from igw3.watson.ibm.com(129.34.139.18) by gauntlet.fv.com via smap (3.2) id xma022188; Fri, 22 Nov 96 13:46:41 -0800 Received: from mailhub1.watson.ibm.com (mailhub1.watson.ibm.com [9.2.249.31]) by igw3.watson.ibm.com (8.7.6/8.7.1) with ESMTP id QAA10426; Fri, 22 Nov 1996 16:43:05 -0500 Received: from hawpub.watson.ibm.com (hawpub.watson.ibm.com [9.2.90.19]) by mailhub1.watson.ibm.com (8.8.2/11-10-96) with SMTP id QAA553766; Fri, 22 Nov 1996 16:42:33 -0500 Received: by hawpub.watson.ibm.com (AIX 3.2/UCB 5.64/6/25/96) id AA59488; Fri, 22 Nov 1996 16:42:33 -0500 From: Uri Blumenthal Message-Id: <9611222142.AA59488@hawpub.watson.ibm.com> Subject: Re: Latest draft of extensible SNMP agent protocol available To: daniele@zk3.dec.com (Mike Daniele) Date: Fri, 22 Nov 1996 16:42:32 -0500 (EST) Cc: agentx@fv.com In-Reply-To: <9611221954.AA10596@bernie.zk3.dec.com> from "Mike Daniele" at Nov 22, 96 02:54:11 pm Reply-To: uri@watson.ibm.com X-Mailer: ELM [version 2.4 PL25] Content-Type: text Mike Daniele says: > >The lack of security is a worry. > > I assume most implementors have a handle on this, since there hasn't > been any push to include security in AgentX (that I recall anyway). Probably this is because of lack of realization of what they're about to face. Like - ordinary "telnet" with no security is sufficiently wide-spread now. "INsecure" IP is sufficiently wide-spread... However, new designs (SHTTP, IPSP, DNSSEC, ...) try to fix the shortcomings of their predecessors. Do you care to recall SNMPv2 WG final days? (:-) I think it's more likely than not, that IESG will not approve a NEW protocol with no security in it. Plus, there is no justification for not having security, honestly. -- Regards, Uri uri@watson.ibm.com -=-=-=-=-=-=-   Delivery-Date: Fri, 22 Nov 1996 14:50:14 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id OAA11678 for X-agentx; Fri, 22 Nov 1996 14:50:13 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id OAA11675 for ; Fri, 22 Nov 1996 14:50:13 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA28320 for ; Fri, 22 Nov 1996 17:51:29 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma028302; Fri, 22 Nov 96 14:51:00 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id OAA28608 for ; Fri, 22 Nov 1996 14:51:10 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id RAA28299 for ; Fri, 22 Nov 1996 17:50:59 -0500 (EST) Message-Id: <199611222250.RAA28299@gauntlet.fv.com> Received: from vnet.ibm.com(199.171.26.4) by gauntlet.fv.com via smap (3.2) id xma028289; Fri, 22 Nov 96 14:50:51 -0800 Received: from UITVM1 by VNET.IBM.COM (IBM VM SMTP V2R3) with BSMTP id 7414; Fri, 22 Nov 96 17:49:37 EST Date: Fri, 22 Nov 96 23:49:20 CET From: "Bert Wijnen" To: daniele@zk3.dec.com, agentx@fv.com Subject: Latest draft of extensible SNMP agent protocol available Ref: Your note of Fri, 22 Nov 96 14:54:11 -0500 Subject: Re: Latest draft of extensible SNMP agent protocol available Mike writes: > >7.2.3 Why do the respponses not have a VarBindList? This prevents the set > >value X get back value Y1 or Y2 or ... paradigm. > > I don't see this paradigm mentioned in section 4.2.5 of RFC 1905... > Do folks think we need to do this? I know Bert won't :-) > Not sure if I understand the question correctly, but it seems to ask if it is possible that a sub receives SET someInstance to value X and that the sub then could return that the value is Y1 or Y2??? Wel, sorry to say, but the return value of a SET can ONLY be the exact same value as that being SET, even if there is an error. RFC 1905 prescribes this, see section 4.2.5 page 18 of RFC1905. Bert   Delivery-Date: Mon, 25 Nov 1996 08:02:06 -0800 Return-Path: Received: (from daemon@localhost) by fv.com (8.7.4/8.7.3) id IAA04463 for X-agentx; Mon, 25 Nov 1996 08:02:05 -0800 (PST) Received: from gauntlet.fv.com (gauntlet.fv.com [207.67.199.118]) by fv.com (8.7.4/8.7.3) with ESMTP id IAA04415 for ; Mon, 25 Nov 1996 08:02:01 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id LAA13142 for ; Mon, 25 Nov 1996 11:03:11 -0500 (EST) Received: from shekel.fv.com(207.67.199.130) by gauntlet.fv.com via smap (3.2) id xma013138; Mon, 25 Nov 96 08:02:43 -0800 Received: from gauntlet.fv.com (gauntlet-in.fv.com [10.0.0.2]) by shekel.fv.com (8.7.5/8.7.3) with ESMTP id IAA17500 for ; Mon, 25 Nov 1996 08:02:54 -0800 (PST) Received: (from uucp@localhost) by gauntlet.fv.com (8.7.5/8.7.3) id LAA13124 for ; Mon, 25 Nov 1996 11:02:41 -0500 (EST) Received: from mail.htconn.com(38.245.21.2) by gauntlet.fv.com via smap (3.2) id xma013112; Mon, 25 Nov 96 08:02:20 -0800 Received: by mail.htconn.com (SMI-8.6/SMI-SVR4) id KAA19877; Mon, 25 Nov 1996 10:59:51 -0500 Date: Mon, 25 Nov 1996 10:59:51 -0500 From: devlinm@mail.htconn.com (T. Max Devlin) Message-Id: <199611251559.KAA19877@mail.htconn.com> To: agentx@fv.com, donryan@microsoft.com Subject: Re: agentx-IndexReserve-PDU From donryan@microsoft.com Mon Nov 18 10:38:52 1996 Resent-From: agentx-owner@fv.com Comment: Posted to the agentx Mailing List To unsubscribe, send mail to agentx-request@fv.com with "unsubscribe" in the Subject Resent-Date: Mon, 18 Nov 1996 04:41:50 -0800 Resent-Message-ID: <18729.848320910.1@fv.com> From: Don Ryan To: "'agentx@fv.com'" Subject: agentx-IndexReserve-PDU Date: Mon, 18 Nov 1996 04:43:13 -0800 X-Suppressed-Encoding: 43 TEXT I do not see how a master agent can be "MIB ignorant" yet know how to allocate new (or any) instances of an index. The comments for this PDU mentions "if v.type is not supported by the master agent" which does not seem very extensible to me. How about: a.) subagent A registers MIB region M containing table T and sets FLAG_ACCEPT_EXTENSIONS to TRUE. b.) subagent B asks master agent for an index in table T c.) since table T is in region M and subagent A accepts extensions master agent forwards request to subagent A (the highest priority dude wins here as in all other cases). in this request the master agent includes something to identify subagent B. d.) subagent A responds to the master agent with the reserved index subagent B requested e.) master agent forwards the reponse to subagent B along with the subagent id of subagent A f.) subagent B registers MIB region with new index and set FLAG_IS_EXTENSION to TRUE Note the master agent does not keep any state expect for an id of each connected subagent. If any subagent closes unexpectedly which registered an extension to another subagent's MIB region, then all extensible subagents will receive an agentx-IndexCleanup-PDU with the id of the dead subagent. The extensible subagents should cleanup all of the resources allocated by the dead subagent (possibly none). If any extensible subagent closes unexpectedly then all subagents with registered extensions will receive an agentx-IndexInvalid-PDU specifying the id of the dead extensible subagent. The subagents should immediately unregister any regions which depended on the dead extensible subagent. In the situation where subagent A is not present, subagent B's index reservation request immediately fails. Subagent B has the option of registering a MIB region using a self-made index or waiting until subagent A comes along before registering it's MIB region. In the situation where subagent A is present but does not support extending table T, the master agent responds to subagent B's request with error TABLE_NOT_EXTENSIBLE and subagent B is hosed until subagent A unregisters. ---------------- This e-mail message was sent to all subscribers to the agentx mailing list. To unsubscribe from this mailing list, please send mail to: agentx-request@fv.com with Subject: unsubscribe your.address@your.domain (NOTE: Please do not reply to this message to unsubscribe. You must send your request to agentx-request@fv.com Thank you.)