[trill] Stephen Farrell's No Objection on draft-ietf-trill-channel-tunnel-10: (with COMMENT)

["Stephen Farrell" <[e-mail]>]

Stephen Farrell has entered the following ballot position for
draft-ietf-trill-channel-tunnel-10: No Objection

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COMMENT:
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- The write up for this and the other trill docs on this
telechat talks about "directory services" but that's not
mentioned in any of the drafts. Pointers to RFC7067 would
probably have saved me a few minutes:-)

- That RFC5869 is not in the downref registry is odd.  I'd
say we should just add it there. It's true though that I
think this seems to be the first stds track doc with it as
normative [1] but I figure it's safe to add with no new LC
stuff.

   [1] http://www.arkko.com/tools/allstats/citations-rfc5869.html

(Apologies that there's no TLS for [1] :-)

- 4.3: Can the verifier deterministically tell from the
context that the keyid here refers to the derived key as
defined in 4.1 and not to (what I guess is) a "bare" key as
per RFC5310? Do you need to say that? 

- 4.4 or section 7: Do we know that there are no issues with
DTLS packets exceeding the MTU but where implementations
won't work, perhaps with a cert chain. DTLS does support
that, but do implementations that are likely to be used
here? If not, maybe a warning is needed. Or, do you need to
warn against cert based ciphersuites on the basis that
nobody knows what to put in certs for trill? Given that you
are (wisely) punting on group communication, maybe you could
also say that only PSK ciphersuites are to be used here for
now, and then also address cert based ciphersuites when you
get around to figuring out group keying?

- section 7, 3rd para: I do worry a bit about that, but
you've called out the risk I guess. If it were possible to
add more guidance as to how to defend in depth that'd be
good I guess.