[Pdns-users] recursor fail to resolve

[Sergio Cesar]

root at ns1:~# host s-s.mx
Host s-s.mx not found: 2(SERVFAIL)

root at ns1:~# cat /var/log/syslog | grep s-s.mx
May  1 09:42:51 ns1 pdns_server[16452]: Remote 216.183.32.162 wants 
's-s/mx.winc.net|A', do = 1, bufsize = 1232 (4096): packetcache MISS
May  1 11:08:43 ns1 pdns_recursor[22995]: 3 [38702/1] question for 
's-s.mx|A' from 216.183.32.182:60383
May  1 11:08:46 ns1 pdns_recursor[22995]: 3 [38702/1] answer to question 
's-s.m |A': 0 answers, 1 additional, took 5 packets, 3106.89 netw ms, 
3110.29 tot ms, 0 throttled, 2 timeouts, 0 tcp connections, rcode=2
May  1 12:14:25 ns1 pdns_recursor[22995]: 3 [39863/1] question for 
's-s.mx|A' from 216.183.32.145:35773
May  1 12:14:28 ns1 pdns_recursor[22995]: 3 [39863/1] answer to question 
's-s.m |A': 0 answers, 0 additional, took 2 packets, 3006.53 netw ms, 
3010.36 tot ms, 0 throttled, 2 timeouts, 0 tcp connections, rcode=2


On 5/1/2020 12:12 PM, Aki Tuomi wrote:
> 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

-- 
--
Sergio Cesar
Technology Director
Wireless Net Connections
Network Communications & Consulting
(956) 380-3536 Office
(956) 587-2377 Mobile