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 adds Proxy-based Fast Handover to Mobile IPv6 (MIPv6). It allows fast handover of a mobile device between mobile access gateway's without the mobile node itself being involved. The document primarily reuses messages flows from a previously defined handover method (RFC 5568), and Proxy Mobile IPv6 (RFC 5213). It also depends on the Security Considerations from RFC 5213 and RFC 5568, which seems appropriate given that the same message flows are used between the same network entities. These existing RFCs describe IPsec ESP as the method for protecting messages, and include details in setting up the SPD and PAD. I believe pointing to those documents for security consideration guidance is generally acceptable. There is one new message flow, which is the forwarding of data packet from the previous mobile access gateway (PMAG) to the next mobile access gateway (NMAG) during transition. The last paragraph in the security considerations section notes that these packets MAY be encrypted with IPsec "if protection of data traffic is required". A better statement might be that they SHOULD be encrypted if the link between the PMAG and NMAG exposes the MN packets to more threats than if they had followed their normal routed path. (One miscellaneous comment: It would be helpful to readers if you added a definition of "Local Mobility Anchor" to the Terminology section.) Brian -- Brian Weis Router/Switch Security Group, ARTG, Cisco Systems Telephone: +1 408 526 4796 Email: bew at cisco.com