Last Call Review of draft-ietf-softwire-public-4over6-09
review-ietf-softwire-public-4over6-09-secdir-lc-kumari-2013-05-30-00

I have reviewed draft-ietf-softwire-public-4over6-09 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.

Given that this is an informational draft documenting existing
practice, I have no serious security concerns with the draft.  FWIW, I
agree with the issue Sean Turner already raised in his discuss, not
that Sean needs my approval.

If the draft gets another spin, the security considerations could
benefit from a bit more text making it clear that the proposed use of
IPv6 address filtering is in the context of the constrained
environment of a single ISP, where such filtering is based on the
ISP's knowledge of its own topology and address allocation scheme.
One can sort of read this between the lines anyway, but it would be
better to make it explicit.