Hi, 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. A number of IPv4 options have become obsolete in practice, but have never been formally deprecated. This document deprecates such IPv4 options, thus cleaning up the corresponding IANA registry, and serving as a basis for providing advice about the filtering of packets containing these options. Additionally, it requests that the status of the corresponding RFCs be changed to "Historic". I have no issues with this document. -derek -- Derek Atkins 617-623-3745 derek at ihtfp.com www.ihtfp.com Computer and Internet Security Consultant