I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. Document editors and WG chairs should treat these comments just like any other last call comments. This document specifies how to delegate IPv6 prefixes to a Mobile Router in a Mobile Network. It has a reasonably extensive Security Considerations section and appears to appropriately specify protective measures against plausible threats. In particular, when the Mobile Router is away from home, it mandates the use of IPsec a la MIPv6. Possibly someone more familiar with IPsec should look at the specified Security Policy Database and Security Association Database. Trivia: Section 3.1, page 5, "...currently used by the is about to expire..." ? perhaps "...by the Mobile Node..." "an Mobile" -> "a Mobile" Various acronyms, such as BU, HoA, while usually explained when first used, are missing from Section 2. HoA is not explained at all. Even better would be to vastly reduce the overuse of acronyms throughout this document. Thanks, Donald