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. Sorry for getting this out so late. I'm a bit confused by this doc -- in particular, I'm not understanding how the Remote ID field is being set so that querying based on it gives a complete set of relevant leases. I'm also wondering if the use case envisioned (filtering spoofed source addresses based on the assumption that you can collect a complete list of leases using this method) is dangerous -- at the very least, it suggests that authentication of the queries here is every more important than in 4388. Furthermore, what risks are there if answers to these queries are spoofed away? In this model, could a relay agent be induced to filter out a legitimate client for want of an answer to a DHCPLEASEQUERY? Also, I'm not a fan of referral Security Considerations sections -- I'd rather see a repeat of the text than a reference. -- Sam