http://bugzilla.mozilla.org/show_bug.cgi?id=248828 Summary: Mozilla might be using the deprecated ip6.int name resolution method

My mail client and mail server machines are, again since recently, both ipv6-enabled. Since then, I open mozilla mail, get the message "conncted to [server], watch a long (20-40 sec) hang and then get my password prompt.

This behaviour is very typical of hanging DNS queries waiting to time out, so I enabled hysterical DNS logging to see what's going on. Trying to check mail, I get entries like this:

Jun 27 17:59:33.568 lame-servers: lame server resolving 'b.8.9.7.e.a.e.f.f.f.4.2.0.a.2.0.6.8.1.0.0.0.f.1.0.7.4.0.1.0.0.2.ip6.int' (in '6.8.1.0.0.0.f.1.0.7.4.0.1.0.0.2.ip6.int'?): [lame_server_IP#port]

That IP that can't be resolved is my mozilla mail client. The lame server (IPv4 IP omitted) is the secondary for the same domain.

I can't figure whether it's the mail server (courier 0.45.4) or mozilla using the obsolete ip6.int query, but I do know that this is what is causing my hangs. So I'm filing the bug against both mozilla and courier.

BTW, the secondary that made this query is BIND 9.2.2 and I assume that it just forwarded the query as it got it, without changing it. However, I know too little about BIND to guarantee this.

The same mail client and mail server were also IPv6-enabled a couple of months ago and this was not happening then. At that time, mozilla was 1.4.2 or 1.6 (not sure which), while courier and BIND were the same as now. This fact seems to point a finger at mozilla, but there are too many steps involved here, I can't figure it conclusively.

Waiting for this to be resolved I guess I'll go write ip6.int PTR records as a workaround...

Z