Ok,
The problem appears to be that dns recursion was not turned on on my dns
server. When I turned that on all started to work as expected.
Regards
On 1 March 2012 23:42, Gerhardus Geldenhuis
<gerhardus.geldenh...@gmail.com>wrote:
> Thanks,
> Your strace examples are imminently more useful I just need to make sense
> of the output. For some reason even though it seems that host is getting
> the right answer it still tries the second dns server specified.
>
> I also get:
> 2522 23:15:39 bind(20, {sa_family=AF_INET, sin_port=htons(0),
> sin_addr=inet_addr("0.0.0.0")}, 16) = 0
> 2522 23:15:39 recvmsg(20, 0x41753ef0, 0) = -1 EAGAIN (Resource
> temporarily unavailable)
>
> which is a bit strange.
>
> Will investigate a bit further tomorrow when I am thinking clearly again.
>
> Regards
>
>
> On 1 March 2012 16:52, Hugh Brown <hbr...@divms.uiowa.edu> wrote:
>
>>
>>
>>>> strace -v -o filename host myserver.example.com
>>>
>>> Regards
>>>
>>
>>
>> strace -fvvvto filename -s 2048 <cmd>
>>
>> is my usual form of calling strace when I don't know what I want from
>> strace. I think you want to add a -f to follow any forked processes at the
>> least.
>>
>>
>> When I set up a bogus nameserver in my resolv.conf and strace it, I see
>> resolv.conf get read and then I see a
>>
>> sendmsg(20, {msg_name(16)={sa_family=AF_**INET, sin_port=htons(53),
>> sin_addr=inet_addr("192.168.1.**2") ...
>> and then later, I see a few -1 EAGAIN Resource temporarily unavailable.
>>
>> Next I see it attempt a sendmsg to the next IP in the list which gives it
>> an answer in a recvmsg a few lines down.
>>
>> If I put a correct nameserver back in resolv.conf and redo the strace, I
>> only see it attempt the first.
>>
>> So, a shortened version of strace that would just track the sendmsg call
>> would be
>>
>> strace -f -e sendmsg -s 2048 host myserver.example.com
>>
>>
>> If I don't do it with the -f flag, then I don't see the query process
>> happening.
>>
>>
>> Hugh
>>
>> ______________________________**_________________
>> rhelv5-list mailing list
>> rhelv5-list@redhat.com
>> https://www.redhat.com/**mailman/listinfo/rhelv5-list<https://www.redhat.com/mailman/listinfo/rhelv5-list>
>>
>
>
>
> --
> Gerhardus Geldenhuis
>
--
Gerhardus Geldenhuis
_______________________________________________
rhelv5-list mailing list
rhelv5-list@redhat.com
https://www.redhat.com/mailman/listinfo/rhelv5-list
