Last Call Review of draft-ietf-ipsecme-ikev2-fragmentation-05
review-ietf-ipsecme-ikev2-fragmentation-05-secdir-lc-atkins-2014-04-10-00

Hi,

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 describes the way to avoid IP fragmentation of large
   IKEv2 messages.  This allows IKEv2 messages to traverse network
   devices that don't allow IP fragments to pass through.

I see no major issues with this document.

There is still a minor issue where you move the exhaustion attack from
the IP layer to the IKE layer -- an attacker could, theoretically,
fill an IKE session with incomplete fragments causing it to use
resources waiting for missing fragments.

-derek
-- 
       Derek Atkins                 617-623-3745
       derek at ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant