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. This document clarifies the Zero Window Probes (ZWP) described in Requirements for Internet Hosts [RFC1122]. In particular, it clarifies the actions that can be taken on connections which are experiencing the ZWP condition. The security considerations section should refer to section 4 as a description of the DoS attack, not section 3. Although it should still refer to section 3. Honestly, I find it confusing that the attack is described after some of the mitigation techniques. It would make the document flow better, IMHO, if you describe the attack and then describe how to mitigate the attack. The document also mentions orphaned connections but does not mention how to mitigate an attack against systems that have orphaned connections. -derek -- Derek Atkins 617-623-3745 derek at ihtfp.com www.ihtfp.com Computer and Internet Security Consultant