[Pdns-users] Recursive lookups over IPv6 failing

[Brielle Bruns]

Hello all,

I've got a weird issue, don't know if its come up before, and i'm not 
exactly sure where to file a bug report about it either.

Server: 2.9.22 (Debian 2.9.22-3 package from sid, recompiled for lenny)
Recursor: 3.2 (Debian 3.2-1 package from sid, recompiled for lenny)
Backends: gmysql

I've got a dual stack host that runs both authorative and recursive 
(yes, I know they should be separate) services, with auth running on 
TCP/UDP 53, and recursive running on TCP/UDP 8053.  Server is set to 
forward queries to 8053 for the recursor to handle. IPv4 and IPv6 ranges 
involved are allowed to query/recurse on the server.

Querying from IPv6 host on the same LAN to the server:

 > www.apple.com
;; Got SERVFAIL reply from 2001:470:e867::3, trying next server

It then tries the same server over ipv4, and is successful.

Try it another time, same exact results.  Try it a third time, and it is 
successful, returning the expected non-auth answers.

Logs show the following:

Apr  2 13:02:57 snowbank pdns[9084]: Not authoritative for 
'www.apple.com', sending servfail to 2001:470:e867::2 (recursion was 
desired)
Apr  2 13:03:57 snowbank pdns[9084]: Not authoritative for 
'www.apple.com', sending servfail to 2001:470:e867::2 (recursion was 
desired)

With no log entry for the third time querying.  It does _not_ do this 
when querying over ipv4 - only over ipv6.  I can reproduce this from any 
ipv6 host for any non-auth domain.


The whole 2 out of 3 queries failing thing is a bit odd.  Anyone have 
any insight or things I should try?

-- 
Brielle Bruns
The Summit Open Source Development Group
http://www.sosdg.org    /     http://www.ahbl.org