module ietf-netconf-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-server";
prefix "ncs";
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
import ietf-x509-cert-to-name {
prefix x509c2n;
reference
"RFC 7407: A YANG Data Model for SNMP Configuration";
}
import ietf-ssh-server {
prefix ss;
revision-date 2018-09-20; // stable grouping definitions
reference
"RFC YYYY: YANG Groupings for SSH Clients and SSH Servers";
}
import ietf-tls-server {
prefix ts;
revision-date 2018-09-20; // stable grouping definitions
reference
"RFC ZZZZ: YANG Groupings for TLS Clients and TLS Servers";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web:
WG List:
Author: Kent Watsen
Author: Gary Wu
Author: Juergen Schoenwaelder
";
description
"This module contains a collection of YANG definitions for
configuring NETCONF servers.
Copyright (c) 2017 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2018-09-20" {
description
"Initial version";
reference
"RFC XXXX: NETCONF Client and Server Models";
}
// Features
feature listen {
description
"The 'listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF client connections
using at least one transport (e.g., SSH, TLS, etc.).";
}
feature ssh-listen {
description
"The 'ssh-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over SSH
client connections.";
reference
"RFC 6242:
Using the NETCONF Protocol over Secure Shell (SSH)";
}
feature tls-listen {
description
"The 'tls-listen' feature indicates that the NETCONF server
supports opening a port to accept NETCONF over TLS
client connections.";
reference
"RFC 7589: Using the NETCONF Protocol over Transport
Layer Security (TLS) with Mutual X.509
Authentication";
}
feature call-home {
description
"The 'call-home' feature indicates that the NETCONF server
supports initiating NETCONF call home connections to
NETCONF clients using at least one transport (e.g., SSH,
TLS, etc.).";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature ssh-call-home {
description
"The 'ssh-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over SSH call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
feature tls-call-home {
description
"The 'tls-call-home' feature indicates that the NETCONF
server supports initiating a NETCONF over TLS call
home connection to NETCONF clients.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF Call Home";
}
// protocol accessible nodes
container netconf-server {
uses netconf-server-grouping;
description
"Top-level container for NETCONF server configuration.";
}
// reusable groupings
grouping netconf-server-grouping {
description
"Top-level grouping for NETCONF server configuration.";
container listen {
if-feature listen;
presence "Enables server to listen for TCP connections";
description "Configures listen behavior";
leaf idle-timeout {
type uint16;
units "seconds";
default 3600; // one hour
description
"Specifies the maximum number of seconds that a NETCONF
session may remain idle. A NETCONF session will be
dropped if it is idle for an interval longer than this
number of seconds. If set to zero, then the server
will never drop a session because it is idle. Sessions
that have a notification subscription active are never
dropped.";
}
list endpoint {
key name;
min-elements 1;
description
"List of endpoints to listen for NETCONF connections.";
leaf name {
type string;
description
"An arbitrary name for the NETCONF listen endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature ssh-listen;
container ssh {
description
"SSH-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
mandatory true;
description
"The IP address to listen on for incoming
connections. The NETCONF server will listen
on all configured interfaces if no value is
specified. INADDR_ANY (0.0.0.0) or INADDR6_ANY
(0:0:0:0:0:0:0:0 a.k.a. ::) MUST be used when
the server is to listen on all IPv4 or IPv6
addresses, respectively.";
}
leaf port {
type inet:port-number;
default 830;
description
"The local port number to listen on. If no value
is specified, the IANA-assigned port value for
'netconf-ssh' (830) is used.";
}
uses ss:ssh-server-grouping;
}
}
case tls {
if-feature tls-listen;
container tls {
description
"TLS-specific listening configuration for inbound
connections.";
leaf address {
type inet:ip-address;
mandatory true;
description
"The IP address to listen on for incoming
connections. The NETCONF server will listen
on all configured interfaces if no value is
specified. INADDR_ANY (0.0.0.0) or INADDR6_ANY
(0:0:0:0:0:0:0:0 a.k.a. ::) MUST be used when
the server is to listen on all IPv4 or IPv6
addresses, respectively.";
}
leaf port {
type inet:port-number;
default 6513;
description
"The local port number to listen on. If no value
is specified, the IANA-assigned port value for
'netconf-tls' (6513) is used.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"NETCONF/TLS servers MUST validate client
certiticates.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a TLS-
based NETCONF server to map the NETCONF
client's presented X.509 certificate to a
NETCONF username. If no matching and valid
cert-to-name list entry can be found, then
the NETCONF server MUST close the connection,
and MUST NOT accept NETCONF messages over
it.";
reference
"RFC WWWW: NETCONF over TLS, Section 7";
}
}
}
}
}
}
}
}
container call-home {
if-feature call-home;
presence "Enables server to initiate TCP connections";
description "Configures call-home behavior";
list netconf-client {
key name;
min-elements 1;
description
"List of NETCONF clients the NETCONF server is to
initiate call-home connections to in parallel.";
leaf name {
type string;
description
"An arbitrary name for the remote NETCONF client.";
}
container endpoints {
description
"Container for the list of endpoints.";
list endpoint {
key name;
min-elements 1;
ordered-by user;
description
"A non-empty user-ordered list of endpoints for this
NETCONF server to try to connect to in sequence.
Defining more than one enables high-availability.";
leaf name {
type string;
description
"An arbitrary name for this endpoint.";
}
choice transport {
mandatory true;
description
"Selects between available transports.";
case ssh {
if-feature ssh-call-home;
container ssh {
description
"Specifies SSH-specific call-home transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the the DNS resolution results
in multiple IP addresses, the IP addresses
will be tried according to local preference
order until a connection has been established
or until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 4334;
description
"The IP port for this endpoint. The NETCONF
server will use the IANA-assigned well-known
port for 'netconf-ch-ssh' (4334) if no value
is specified.";
}
uses ss:ssh-server-grouping;
}
}
case tls {
if-feature tls-call-home;
container tls {
description
"Specifies TLS-specific call-home transport
configuration.";
leaf address {
type inet:host;
mandatory true;
description
"The IP address or hostname of the endpoint.
If a domain name is configured, then the
DNS resolution should happen on each usage
attempt. If the the DNS resolution results
in multiple IP addresses, the IP addresses
will be tried according to local preference
order until a connection has been established
or until all IP addresses have failed.";
}
leaf port {
type inet:port-number;
default 4335;
description
"The IP port for this endpoint. The NETCONF
server will use the IANA-assigned well-known
port for 'netconf-ch-tls' (4335) if no value
is specified.";
}
uses ts:tls-server-grouping {
refine "client-auth" {
must 'pinned-ca-certs or pinned-client-certs';
description
"NETCONF/TLS servers MUST validate client
certiticates.";
}
augment "client-auth" {
description
"Augments in the cert-to-name structure.";
container cert-maps {
uses x509c2n:cert-to-name;
description
"The cert-maps container is used by a
TLS-based NETCONF server to map the
NETCONF client's presented X.509
certificate to a NETCONF username. If
no matching and valid cert-to-name list
entry can be found, then the NETCONF
server MUST close the connection, and
MUST NOT accept NETCONF messages over
it.";
reference
"RFC WWWW: NETCONF over TLS, Section 7";
}
}
}
}
} // end tls
} // end choice
} // end endpoint
}
container connection-type {
description
"Indicates the kind of connection to use.";
choice connection-type {
mandatory true;
description
"Selects between available connection types.";
case persistent-connection {
container persistent {
presence
"Indicates that a persistent connection is to be
maintained.";
description
"Maintain a persistent connection to the NETCONF
client. If the connection goes down, immediately
start trying to reconnect to it, using the
reconnection strategy.
This connection type minimizes any NETCONF client
to NETCONF server data-transfer delay, albeit at
the expense of holding resources longer.";
container keep-alives {
description
"Configures the keep-alive policy, to
proactively test the aliveness of the SSH/TLS
client. An unresponsive SSH/TLS client will
be dropped after approximately max-attempts *
max-wait seconds.";
reference
"RFC 8071: NETCONF Call Home and RESTCONF
Call Home, Section 4.1, item S7";
leaf max-wait {
type uint16 {
range "1..max";
}
units seconds;
default 30;
description
"Sets the amount of time in seconds after
which if no data has been received from
the SSH/TLS client, a SSH/TLS-level message
will be sent to test the aliveness of the
SSH/TLS client.";
}
leaf max-attempts {
type uint8;
default 3;
description
"Sets the maximum number of sequential keep-
alive messages that can fail to obtain a
response from the SSH/TLS client before
assuming the SSH/TLS client is no longer
alive.";
}
}
}
}
case periodic-connection {
container periodic {
presence
"Indicates that a periodic connection is to be
maintained.";
description
"Periodically connect to the NETCONF client. The
NETCONF client should close the underlying TLS
connection upon completing planned activities.
This connection type increases resource
utilization, albeit with increased delay in
NETCONF client to NETCONF client interactions.";
leaf period {
type uint16;
units "minutes";
default 60;
description
"Duration of time between periodic connections.";
}
leaf anchor-time {
type yang:date-and-time {
// constrained to minute-level granularity
pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}'
+ '(Z|[\+\-]\d{2}:\d{2})';
}
description
"Designates a timestamp before or after which a
series of periodic connections are determined.
The periodic connections occur at a whole
multiple interval from the anchor time. For
example, for an anchor time is 15 minutes past
midnight and a period interval of 24 hours, then
a periodic connection will occur 15 minutes past
midnight everyday.";
}
leaf idle-timeout {
type uint16;
units "seconds";
default 120; // two minutes
description
"Specifies the maximum number of seconds that
a NETCONF session may remain idle. A NETCONF
session will be dropped if it is idle for an
interval longer than this number of seconds.
If set to zero, then the server will never
drop a session because it is idle.";
}
}
}
}
}
container reconnect-strategy {
description
"The reconnection strategy directs how a NETCONF server
reconnects to a NETCONF client, after discovering its
connection to the client has dropped, even if due to a
reboot. The NETCONF server starts with the specified
endpoint and tries to connect to it max-attempts times
before trying the next endpoint in the list (round
robin).";
leaf start-with {
type enumeration {
enum first-listed {
description
"Indicates that reconnections should start with
the first endpoint listed.";
}
enum last-connected {
description
"Indicates that reconnections should start with
the endpoint last connected to. If no previous
connection has ever been established, then the
first endpoint configured is used. NETCONF
servers SHOULD be able to remember the last
endpoint connected to across reboots.";
}
enum random-selection {
description
"Indicates that reconnections should start with
a random endpoint.";
}
}
default first-listed;
description
"Specifies which of the NETCONF client's endpoints
the NETCONF server should start with when trying
to connect to the NETCONF client.";
}
leaf max-attempts {
type uint8 {
range "1..max";
}
default 3;
description
"Specifies the number times the NETCONF server tries
to connect to a specific endpoint before moving on
to the next endpoint in the list (round robin).";
}
}
}
}
}
}