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 is a minor update to RFC4971, in order to correctly support IPv6-only routers. Summary The document is ready for publication. Details The Security Considerations are unchanged from the original RFC and cover the router capability feature reasonably. They still seem to describe this quaint world where each router can rely on all its peers to always send correct information. But at least we recommend to use protocol-level integrity mechanisms in "high risk" situations. Thanks, Yaron