[asterisk-users] DNS

[Rich Adamson]

Ola Lidholm wrote:
> 
> On 25 aug 2006, at 20.18, Bill Gibbs wrote:
> 
>> Asterisk server is setup in /etc/resolv.conf to query my primary and 
>> backup NS.  Had an issue with my primary NS and asterisk refused to 
>> complete any calls or forward inbound calls to extensions.  I had to 
>> manually switch it to look at the backup NS first then reboot for it 
>> to start working while I fixed the primary.  Is this behavior normal 
>> or am I missing a step?  All hosts, etc are identified by IP.
>>
> I have had similar issues.
> 
> To sort of resolve this I had to install a local name-server on the 
> machine that contains the addresses asterisk tries to resolve (changing 
> to using IP-addresses did not fix the issue for me either).
> 
> I would prefer an option in asterisk that tells it to not resolv more 
> than once on each address.

That won't fix the problem. If that's all you needed, then change your 
resolver to use /etc/hosts and statically define each item. However, 
that totally defeats the dynamic purpose of dns.

If you configure the dns server (on each asterisk box) to be a caching 
only server, then it will do the normal dns lookup and cache that 
translation "one time". Asterisk is generally happy with that. However, 
if the owner of the dns name that you're looking up sets an unreasonable 
time-to-live for that name, the caching server isn't going to help much
on a flaky network.