Hi all, (Sorry , it seems to me that the notification was blocked by the filter. I guess it's a little bit late.) I have reviewed draft-ietf-hip-rfc4423-bis-19 as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review. Document editors and WG chairs should treat these comments just like any other last call comments. “This memo describes a new namespace, the Host Identity namespace, and a new protocol layer, the Host Identity Protocol, between the internetworking and transport layers. Herein are presented the basics of the current namespaces, their strengths and weaknesses, and how a new namespace will add completeness to them. The roles of this new namespace in the protocols are defined. This document obsoletes RFC 4423 and addresses the concerns raised by the IESG, particularly that of crypto agility. It incorporates lessons learned from the implementations of RFC 5201 and goes further to explain how HIP works as a secure signaling channel.” My overall view of the document is 'Ready' for publication. Some small ones: 1. Especially, I am glad to see the security consideration part well explained. I guess it's still worth writing something about the security tradeoff influence for the different modes mentioned in previous sections. In fact, there are some words in previous sections, maybe a summary can be put here. 2. It's good to have a single subsection about " Answers to NSRG questions". However, maybe it's better to put it in appendix? Regards, Will (Shucheng LIU)