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 obsoletes RFC 5787 and updates RFC 5786. Though this document is from an area with which I have no expertise, I found it clear and easy to follow. I found no security issues. One minor nit, it'd be helpful if Appendix C provided more detail about the nature of how this draft updates RFC 5786.