Subject: [karp] Comment on draft-mahesh-karp-rkmp

From: William Atwood <[email-masked]>
Date: Tue, 26 Nov 2013 15:01:31 -0500

I have been reading draft-mahesh-karp-rkmp, and I am puzzled by several
issues.  I discuss the first issue below.  Once I understand what is
intended by the authors, I expect to raise the other issues.  (The way
in which I will phrase these issues may depend on the answer to the
first issue.)

>From the name of the draft, I had always assumed that the document was
talking about a "new" Key Management Protocol, called RKMP.  However,
the key phrase in the first paragraph is "defines a mechanism to secure
such pairwise Routing Protocol (RP) associations using IKEv2 [RFC5996]".

After the introduction, the document discusses how the exchanges build
on the messages and exchange formats of IKEv2: where the semantics are
the same, and where the semantics differ.  To my mind, given the
different semantics, the "new" protocol is _not_ IKEv2.  However, the
following text continues to speak of "invoking IKEv2", which would seem
to me to imply "invoking unmodified IKEv2".  However, unmodified IKEv2
has the wrong semantics for what happens to a child SA when the parent
IKEv2 SA is destroyed.

I suspect that what is really happening here is that
draft-mahesh-karp-rkmp is defining _extensions_ to IKEv2, and new
semantics for child SAs when those extensions are used.  The material in
Section 6 seems to support this view.

If this is so, then I suggest that Section 1 needs to be lightly
re-written to make it clear that the document is proposing extensions to
IKEv2, and that references to "IKEv2" in the subsequent text are
references to the extended IKEv2.

Comments from the authors (and anyone else) will be appreciated.  I need
to understand what is actually intended here before I can comment
properly on the rest of the document.

  Bill

-- 
Dr. J.W. Atwood, Eng.             tel:   +1 (514) 848-2424 x3046
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