DNS problems this morning -

[Rick Stevens]

On 11/14/2012 06:45 AM, Tim issued this missive:
> Tim:
>>> I was only trying out the "rotate" option, but it makes no difference
>>> where it is in the file, as far my tests with the dig and nslookup
>>> commands, go.  It may well be that *they* read the resolv.conf file in
>>> their own manner, only looking for nameserver lines.
>>>
>>> Short of reading through the nameserver logs, I can't think of another
>>> tool to test with that tells me which nameserver answered its query.
>>> I'll try that later on.
>
> lee:
>> When you use two name servers and turn on the query logging ('rndc
>> querylog on') on at least one of them, you can see if the one that
>> logs the requests has answered one or not.
>>
>> Also, dig tells you which server answered and how long it took:
>
> Methinks you didn't read what I wrote.  I tested using dig and nslookup,
> I already knew that they tell which server answered, they told me that
> the same one kept answering.  Nor, noticed where I mentioned the timing
> of results, in an earlier message.
>
> So, either those tools behave differently than other things doing name
> lookups on the system, or the system ignores the directive to
> round-robin the lookups.
>
> Which means doing a test with another tool, and looking at the logs,
> which I haven't done yet as I've been otherwise occupied.

If you're testing these options, you must disable nscd (if it's
running). nscd will interpose itself in the resolver library chain
and answer resolver queries from its cache first. I don't know if
nscd handles the options line(s) in the resolv.conf at all.
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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
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