Early Review of draft-ietf-lisp-crypto-06
review-ietf-lisp-crypto-06-rtgdir-early-mcpherson-2016-08-25-00

RTG-DIR REVIEW: draft-ietf-lisp-crypto-06.txt

Hello,

I have been selected as the Routing Directorate reviewer for this draft. The
Routing Directorate seeks to review all routing or routing-related drafts as
they pass through IETF last call and IESG review, and sometimes on special
request. The purpose of the review is to provide assistance to the Routing ADs.
For more information about the Routing Directorate, please see
http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it would
be helpful if you could consider them along with any other IETF Last Call
comments that you receive, and strive to resolve them through discussion or by
updating the draft.

Document: draft-ietf-lisp-crypto-06.txt

Reviewer: Danny McPherson

Review Date: August 24, 2016

Intended Status: Experimental

Summary:

 I have some minor concerns about this document that should be considered
 before publication.

Comments:

I believe the draft is technically sound.

Major Issues:

I have no “Major” issues with this I-D.

Minor Issues:

In the Security Considerations section a small amount of text might be useful
that discusses end-end v. encryption from middle boxes, and the risks therein. 
There are clearly benefits to this over no encryption, but there are risks
about assumptions that may be made thereafter as well.

Nits:

S.1: s/typically not modified.  Which means/typically not modified, which means/

S.1: Is there in fact a case where asymmetries result in the *same* egress xTRs
but different keys are used?  I believe this would just apply to "different
xTRs", no?  :

        However, return traffic uses the same procedures but with different key
        values by the same xTRs or potentially different xTRs when the paths
        between LISP sites are asymmetric.

S.1: Regarding "[t]his document has the following requirements for the
solutions space", it might be useful to reference some general IETF privacy
work, even RFC 6973 or the like.  Given that it's Experimental I think it's
fine as is, but some references for the broader community may be in order.  In
particular, references to not requiring a separate PKI (and therefore external
or circular dependencies!), avoiding third party trust anchor, rekeying as good
operational practice, not just compromises,  and other such arguments might be
reinforced.

S.3: Could include LCAF here, perhaps.

S.4: You could probably strike this entire sentence and lessen confusion: "When
an ETR (when it is also an ITR) encapsulates packets to this ITR (when it is
also an ETR), a separate key exchange and shared-secret computation is
performed.”

S.7: It’s unclear what constitutes “Diffie-Hellman *group*”.

S.7: s/the the/the/

S.7: s/integrity-check/integrity check/

S.8: Editors note to strike text in last paragraph here, unclear what
resolution was from this text.

S.12.1: A reference to the SAAG comments might be useful here?

S 13: Are you sure you want a default FCFS allocation policy here and not a
slightly higher bar?

Throughout: Consistent hyphenation in the document would help (e.g.,
“network-byte” ..).

Throughout: Expanding on first use of each acronym would be useful, perhaps
with references.