Re: qpsmtpd-async weird ParaDNS lookup problem

Do you have ParaDNS::XS installed? If not, try installing it. It's 
generally likely to be better than plain ParaDNS (and will be used 
automatically if it's installed).

On Thu, 17 Jul 2014, David Favor wrote:

> I've been running qpsmtpd-async for years on all sorts of servers.
>
> Likely I have something in DNS setup slightly wrong on a new server
> I'm setting up + what's wrong escapes me.
>
> The symptom is qpsmtpd-async hanging forever in the HELO sequence.
>
> Both forkserver + prefork work fine + async works so much better,
> I'd like to resolve this problem.
>
> Here's an example of the problem...
>
> Listen child making a Qpsmtpd::PollServer for 7.
> 11869 in config(plugins)
> 11869 config(plugins) returning (resolve_sender_host 
> dont_require_anglebrackets rcpt_simple [email protected] [email protected] 
> [email protected] [email protected] [email protected]
> [email protected] [email protected] maildir /cluster/clients/ivan-budimir 
> %d/users/%l/Maildir) from cache
> DNS failure looking for 127.0.0.1 after 0 secs (looked for 1, got 0)
> 11869 (connect) running plugin: resolve_sender_host
> 11869 (connect) resolve_sender_host: DEBUG: ip=127.0.0.1 host=localhost 
> domain=localhost
> 11869 Plugin resolve_sender_host, hook connect returned DECLINED,
> 11869 in config(smtpgreeting)
> 11869 config(smtpgreeting) returning (Ready!) from cache
>
> Notice this line emitted from ParaDNS...
>
>   DNS failure looking for 127.0.0.1 after 0 secs (looked for 1, got 0)
>
> Bind looks good...
>
>   biz-net2# netstat -pluten | grep named
>   tcp        0      0 127.0.0.1:53            0.0.0.0:*               LISTEN 
> 105        6068        4715/named
>   tcp        0      0 127.0.0.1:953           0.0.0.0:*               LISTEN 
> 105        6073        4715/named
>   tcp6       0      0 ::1:53                  :::*                    LISTEN 
> 105        6070        4715/named
>   tcp6       0      0 ::1:953                 :::*                    LISTEN 
> 105        6074        4715/named
>   udp        0      0 127.0.0.1:53            0.0.0.0:* 
> 105        6067        4715/named
>   udp6       0      0 ::1:53                  :::* 
> 105        6069        4715/named
>
> And host seems to work too...
>
>   biz-net2# host localhost
>   localhost has address 127.0.0.1
>   localhost has IPv6 address ::1
>
>   biz-net2# host 127.0.0.1
>   1.0.0.127.in-addr.arpa domain name pointer localhost.
>
> If I turn on ParaDNS debugging (export PARADNS_DEBUG=100) I just see the 
> lookup fail again...
>
>   100/2 [17636] dns lookup: Trying to resolve A: 127.0.0.1
>   100/2 [17636] dns lookup: NS Query: 127.0.0.1 (60806)
>   DNS failure looking for 127.0.0.1 after 0 secs (looked for 1, got 0)
>
> biz-net2# perl -MParaDNS -e 'print "$ParaDNS::VERSION\n"'
> 2.0
>
> Anyone have any suggestions?
>
>