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 describes current practices for configuring DHCP in complex network scenarios, where the goal is to allow servers to configure DHCP clients differently depending on the client's network location. Summary This is a very extensive document, but the security considerations do not do it justice. Details The Security Considerations section is essentially empty, saying only that drafts that define DHCP options each include their own security considerations. However this document references 12 other RFCs (and they in fact do have substantial security considerations) so this leaves the reader to research the matter on her own. Moreover, the technology covered spans more than 20 years (15 years, counting only Relay Agent Information), and security best practices have changed. Old security recommendations may not be today's best practices, and some previously recommended mechanisms may have never materialized in real-world deployment. This document is basically a survey of best practices in deploying DHCP in complex networks. As such, I would expect the Security Considerations section to include: - Recommendations about which configuration practices are to be preferred from a security point of view. - Up to date security recommendations in summary form, at least for the main use cases covered. - An architectural view, at the same level as the rest of the document, of how these configurations interact with common security practices like firewall-based network separation or NAC. I realize that the document is 3 years old and everyone just wants to see it published, but in my opinion it is incomplete in its current form. Thanks, Yaron