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 I'm late with this review.

This document defines a heartbeat protocol for Proxy Mobile IPv6
"anchors" (LMA -- Local Mobility Anchor) and "gateways" (MAG -- Mobility
Access Gateway).

These heartbeat messages carry no information that is useful to
eavesdroppers, and are sent relatively infrequently (no more often than
every 30 seconds).  Heartbeats are used to detect dead/restarted
LMAs/MAGs.

I have found no security issues with this document.

Nico
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