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 expired doc has been in the secdir queue for some time. It's not clear what the current state is, but I gave it a once-over now and will look at it again if it's ever revived. While the security considerations sectional is minimal, that's generally fine for an informational doc such as this. That said, I would like to see more thought given to malicious RAs and whether each of these methods could be effectively applied against them (e.g. how easy is each to subvert?). And if none of the methods are applicable, as the current security considerations says, then also call that out in the abstract and intro. Second, I'm surprised that the only end-host based solutions are staticly-configured packet filters (3.7) and delays (3.9). Why not simply "try, try again": accept multiple RAs, see which ones work, and discard (or at least don't use) the rest? Lastly, the table in section 4 is a little unclear: does "Y" mean "helps (somewhat)" or "is completely sufficient"? I think it means the former, but clarity would be good.