comments about morishita-dnsop-misbehavior-against-aaaa-00

[Pekka Savola <pekkas@netcore.fi>]

Hi,

A few comments on:

       Common Misbehavior against DNS Queries for IPv6 Addresses
         draft-morishita-dnsop-misbehavior-against-aaaa-00.txt

In short, I think this is a very well written and a very useful document.  
I was surprised why it wasn't on the DNSOP agenda in Vienna.

In any case, down to the comments..

substantial
-----------

4.1 Return NXDOMAIN
                                                                                                  
   This type of server returns a response with the RCODE being 3
   (NXDOMAIN) to a query for a AAAA RR, indicating it does not have any
   RRs of any type for the queried name.  In fact, such a server
   apparently returns NXDOMAIN to all queries except those for an A RR.

and:

4.3 Ignore Queries for AAAA
[...]
   Again, these servers apparently ignore all queries except those for
   an A RR.

==> is this really the case?  Do these servers *also* ignore or return an 
error to queries for NS, MX, SOA, and other resource records (and the text 
was slightly inaccurate), or does it really, really break everything 
except A records (whoops, maybe add a few words of clarification to 
underline that).

4.2 Return NOTIMP
                                                                                                  
   Other authoritative servers return a response with the RCODE being 4
   (NOTIMP), indicating the servers do not support the requested type of
   query.

[...]

  Using SERVFAIL or FORMERR would cause the same effect, though the
   authors have not seen such implementations yet.
                                                                                                  
==> I recall faintly that e.g. bind 4.9 series prior to patching some
years ago returned SERVFAIL?  Maybe also have a look at: 
http://www.wcug.wwu.edu/lists/ngtrans/200110/msg00123.html


semi-editorial
--------------

In the following sections, this
   memo describes some typical cases of the misbehavior, the rationale,
   and (bad) effects of them.

==> "them" is an ambiguous referral.  Does it refer to the both 
misbehaviour and the rationale?  Based on the memo, it looks like it 
should only refer to the misbehaviour, because the document doesn't 
generally look at the (bad) effects of the _rationale_ (why the DNS 
queries are mishandled, which is typically just due to bugs or whatnot).



editorial
---------

This memo describes details of the known cases and
   discusses the effect.

==> s/effect/effects of these cases/ (seems to end a bit abruptly?)

   Many DNS clients (resolvers) that support IPv6 first search for AAAA
   RRs (Resource Records) of a target host name, and then for A RRs of
   the same name.

s/RRs (Resource Records)/Resource Records (RRs)/

Thus, if a DNS server which is responsible for the
   name is not compliant to the specifications

==> s/to/with/ (I've seen both but I think that with is better)?

 In some cases, for example, a web browser fails to connect
   to a web server otherwise it could.

==> s/otherwise it/it otherwise/ ?

The examples are for informational purposes
   only, and the authors do not intend accusation against any
   implementations or zone administrators described in this memo.

==> s/intend accusation against/intend to accuse/

4.4 Return a Broken Response
                                                                                                  
   Some other type of authoritative servers return broken responses to
   AAAA queries.

==> s/type/types/ ?

Full Copyright Statement

==> add the IPR boilerplate section before this?

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings


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