CentOS - Jan 2015 - Squid3 on CentOS 6.6: IPv6 PTR endianess

Hello,

I'm running a Squid cache (Version 3.1.10) on CentOS 6.6 as a forward proxy
which is reachable over a global IPv6 address.
For whatever reason, Squid tries to perform PTR lookups on the client's IPv6
address.

The weird thing is, that Squid seems to struggle with the "endianess"
of the IPv6 address blocks.
For example:

My current client IP is 2003:6e:d79:2104:7163:7ecd:9333:f0be.
Squid tries to resolve
b.e.f.0.3.3.9.3.c.d.7.e.6.3.7.1.0.4.2.1.7.9.0.d.6.e.0.0.0.3.2.0.ip6.arpa.
That means:

    b.e.f.0.3.3.9.3.c.d.7.e.6.3.7.1.0.4.2.1.7.9.0.d.6.e.0.0.0.3.2.0.ip6.arpa
->  0.2.3.0.0.0.e.6.d.0.9.7.1.2.4.0.1.7.3.6.e.7.d.c.3.9.3.3.0.f.e.b
->   0230 :  00e6 :  d097 :  1240 :  1736 :  e7dc :  3933 :  0feb

For comparison:

Squid:	0230:00e6:d097:1240:1736:e7dc:3933:0feb
Real:	2003:006e:0d79:2104:7163:7ecd:9333:f0be

It seems, that Squid just messes with the order of the Bytes on each block.

I couldn't find any related bug report on this (checked Squid and CentOS bug
tracker), so I'm not sure if it's
a CentOS or Squid related problem.

Is anyone else experiencing this? It seems to be happen on IPv6 client addresses
only - with IPv4 it works just fine.
And besides of these broken PTR lookups Squid is working as expected.



Greetings from Wuppertal
 Max

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Hey Max,

You are using squid 3.1.x which is not supported anymore by the squid 
development team.
It is possible that there is a bug in this version of squid and that it 
was not reported until now.
Squid should not run a PTR record lookup unless there is an acl which 
requires\wants\needs it.

Details on squid for CentOS at:
http://wiki.squid-cache.org/KnowledgeBase/CentOS

In any case the better place to seek for an answer on the issue you have 
described is in the squid-users mailing list.

All The Bests,
Eliezer Croitoru

On 31/01/2015 20:36, Max Grobecker wrote:
> Is anyone else experiencing this? It seems to be happen on IPv6 client
addresses only - with IPv4 it works just fine.
> And besides of these broken PTR lookups Squid is working as expected.
>
>
>
> Greetings from Wuppertal
>   Max