Subject: [DNSOP] [TCP] Review of draft-ietf-dnsop-5966bis-00.txt

From: Stephane Bortzmeyer <[email-masked]>
Date: Sun, 4 Jan 2015 18:42:26 +0100

On Thu, Dec 04, 2014 at 05:58:01AM -0800,
 [email-masked] <[email-masked]> wrote 
 a message of 37 lines which said:

>         Title           : DNS Transport over TCP - Implementation Requirements

One month later... Sorry.

I have read draft-ietf-dnsop-5966bis-00 and I like it. I think the
general idea (not just supporting TCP but having it working as well as
UDP is both realistic, and in the right direction. The document is
short (a good thing, in my book) and to the point. I do not find
errors or problems.

Some issues:

Section 3, "some network devices deliberately refuse to handle DNS
packets containing EDNS0 options" Isn't it true of DNS-over-TCP as
well? SAC035 is pessimistic (see table 2). Do we have other data on
TCP (lack of) support in middleboxes?

Section 11, the Security Considerations does not mention an important
reason to use TCP: completely solving reflection attacks. 

In the same section, should we add a word about poisoning attacks?
AFAIK, at least one resolver, CNS, switches to TCP when it receives
too many answers with the wrong Query ID. Should we document that the
use of TCP may make poisoning more difficult?

Editorial: 

Section 8, TCP fastopen is now a RFC, RFC 7413