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Re: current usage of AAAA implicit MX?

2008-04-04 13:48:43

On Fri, 4 Apr 2008, Arnt Gulbrandsen wrote:

Michael Storz writes:
- number of MTAs from which we accepted emails over IPv6: 255

Perhaps you could take the email addresses sent to you by those MTAs and
see how many have MX records, how many only A and how many only AAAA?

Arnt


Ok, I've done that. It took some time and I don't know if it is helpful.

From the 255 MTAs, I got emails with 504 different domains in 'mail from'
(I excluded the outgoing servers of the german ISP freenet.de, because it
would distort the statistik).

160 domains have a path back over IPv6, 155 via MX RRs and 5 via A/AAAA
RRs only:

ok: art.wga.hu -A->    148.6.0.90 -PTR-> art.wga.hu
no:                               -PTR-> www.hung-art.hu -A-> 148.6.0.90
ok:            -AAAA-> 2001:738:5001:0:0:0:0:90 -PTR-> art.wga.hu
no:                                             -PTR-> www.hung-art.hu -AAAA-> 
2001:738:5001:0:0:0:0:90

no: mail.imc.org -A->    192.245.12.227 -PTR-> Balder-227.Proper.COM -A-> 
192.245.12.227
no:              -AAAA-> 2001:470:1F04:392:0:0:0:2 -PTR-> 
properopus-pt.tunnel.tserv3.fmt2.ipv6.he.net -AAAA-> NXDOMAIN

ok: mail.utef.cvut.cz -A->    147.32.68.12 -PTR-> mail.utef.cvut.cz
ok:                   -AAAA-> 2001:718:2:2600:0:0:0:3 -PTR-> mail.utef.cvut.cz

no: mailman.teg-ev.de -A->    193.99.159.73 -PTR-> teg.v-pe.de -A-> 
193.99.159.73
no:                   -AAAA-> 2001:600:1003:1:0:0:0:73 -PTR-> teg.v-pe.de 
-AAAA-> 2001:600:1003:1:0:0:0:73

ok: s5.stud.ku.dk -A->    130.225.126.137 -PTR-> s5.stud.ku.dk
ok:               -AAAA-> 2001:878:100:12:0:0:0:137 -PTR-> s5.stud.ku.dk

3 of them are the email servers of their domain without host subdomain:

% dig +short imc.org mx
5 mail.imc.org.
% dig +short utef.cvut.cz mx
10 regulus.utef.cvut.cz.
% dig +short regulus.utef.cvut.cz AAAA
mail.utef.cvut.cz.
2001:718:2:2600::3
% dig +short teg-ev.de mx
0 mail.teg-ev.de.
% dig +short mail.teg-ev.de AAAA
2001:600:1003:1::73

From the 155 MX RRs

- 58 MX RRs, where all hosts have A + AAAA RRs
- 44 MX RRs, which point to one host which has A + AAAA RRs
- 43 MX RRs, where at least one of the backup MX has only A RRs, all
  others with A and AAAA RRs
- 5 MX RRs, where the primary has only A RRs, but backup has A and AAAA
  RRs
- 5 MX RRs with mixed hosts, same prio but some have only A RRs other both
- 0 MX where one of the hosts has only an AAAA RR, which means
  prioritizing a protocol is not used

and

- 3 of the MX point to themselves, which means the domains are hosts with
MX RRs.

Michael Storz