I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. This document describes a method to protect a network from router/link failures by encapsulating packets in an envelope that denotes what nodes it should *not* be routed through. This is not a protocol definition (despite a few stray MUSTs), it is only an informational summary of design issues and a framework. Summary The document is good to go. In fact, a SecDir review is not applicable. Details The document does contain a Security Considerations section that goes through 3 potential security issues. But since the document in general is a high-level discussion, it is impossible to analyze whether all pertinent security issues are covered. If the not-via mechanism is ever specified as a protocol, the security analysis will need to be done from scratch. Thanks, Yaron