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Document: draft-ietf-dnsop-edns-tcp-keepalive-04.txt
Reviewer: Brian Carpenter
Review Date: 2015-11-23
IETF LC End Date: 2015-11-30
IESG Telechat date:

Summary: Ready with issues
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Comment: These are only standards-language issues, nothing fundamental.
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Major Issues:
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Last paragraph of section 3.2.2.  Receiving Responses:

   A DNS client that sent a query containing the edns-keepalive-option
   but receives a response that does not contain the edns-keepalive-
   option should assume the server does not support keepalive and behave
   following the guidance in [DRAFT-5966bis].  This holds true even if a
   previous edns-keepalive-option exchange occurred on the existing TCP
   connection.

Firstly, shouldn't that "should" be a SHOULD?

More important, [DRAFT-5966bis] really looks like a normative reference to me.
I couldn't code this without reading that reference. It's already entering
Last Call so hopefully this won't waste much time.

Section 3.6.  Anycast Considerations:

   ...
   Changes in network topology between clients and anycast servers may
   cause disruption to TCP sessions making use of edns-tcp-keepalive
   more often than with TCP sessions that omit it, since the TCP
   sessions are expected to be longer-lived.  Anycast servers MAY make
   use of TCP multipath [RFC6824] to anchor the server side of the TCP
   connection to an unambiguously-unicast address in order to avoid
   disruption due to topology changes.

IMHO, [RFC6824] is another normative reference; and it's a downref since
it's an Experimental RFC. I think you could avoid this by weakening
the last sentence a bit:

   It might be possible for anycast servers to avoid disruption due to
   topology changes by making use of TCP multipath [RFC6824] to anchor
   the server side of the TCP connection to an unambiguously unicast address.