[Pdns-users] recursor fail to resolve

[Aki Tuomi]

Next step, try to resolve s-s.mx and check your logs. Like /var/log/syslog?

Aki

> On 05/01/2020 7:09 PM Sergio Cesar <sergio at winc.net> wrote:
> 
>  
> Thank you for the reply.
> 
> Here it is, not sure what that means.
> The recursor is running on the same server as the PDNS with a different 
> IP address.  if that makes a difference.
> 
> root at ns1:~# rec_control trace-regex s-s.mx
> ok
> ok
> ok
> 
> On 5/1/2020 11:37 AM, Aki Tuomi wrote:
> >> On 05/01/2020 6:31 PM Sergio P Cesar via Pdns-users <pdns-users at mailman.powerdns.com> wrote:
> >>
> >>   
> >> I am new with pdns, just installed a resolver 4.3.0-rc2 to learn and all
> >> seems to work but stumbled into an issue I cant resolve.
> >>
> >> My mailserver failed to deliver email to a few domains, in tracking it I
> >> found that their DNS will drop the first packet on every new query  but
> >> will respond on a second query ok and every one after that. (5 minutes
> >> timeout) it will drop the 1st packet again.
> >> I was expecting the recursor to query the 2nd and 3rd server in their
> >> list but it does not look like it is doing that.
> >> It seems like it is caching the failure and does not query again at all
> >> for a while.
> >> I changed packetcache-servfail-ttl=0 and now it looks like after the 3rd
> >> query attempt it will work as the far end server now respond.
> >> Not sure this is correct setting  or I will have adverse effect setting
> >> this to 0.
> >>
> >> Perhaps I have not set something else that will tell the recursor to try
> >> the next server if the first one fail to respond or send a second packet
> >> or a retry.
> >> I used bind to test and it gets a response on the first try. I did not
> >> try to trace the packets from a bind query.
> >>
> >> Thanks
> >>
> >>
> >
> > Try `rec_control trace-regex domain.com` and post that. Without censoring the results.
> >
> > Aki