[asterisk-users] Losing local SIP phones when internet goes down?

[Jeff LaCoursiere]

On Fri, 5 Feb 2010, Nikhil Nair wrote:

> Hi again,
>
> OK, I've now installed a local caching nameserver, but don't see any
> change at all.
>
> IN detail, what I did:
>
> - Installed Debian packages resolvconf and dnsmasq (resolvconf just takes
> care of dynamic nameserver allocations in /etc/resolv.conf).
>
> - After looking at the docs, edited /etc/network/interfaces to add a
>   dns-nameservers line in the entry for eth1.  Then reconfigured
>   resolvconf.
>
> - Checked /etc/resolv.conf: now showing 127.0.0.1 as the only nameserver.
>
> - Tested name resolution in general: working fine.
>
> - Turned ADSL router off and tried to make local and Zap calls: no luck.
>
> - Rebooted machine and tried again: still no luck.
>
> Again, the logs indicate that Asterisk thinks the SIP phones are
> unreachable.
>
> Was there anything special I needed to do with the setup of dnsmasq, or
> its interface with Asterisk?  If not, I'm stuck again.
>
> Thoughts?
>
> Nikhil.
>

Hi,

I am stepping out on a limb here, since I have never run dnsmasq, but I 
don't think it is an actual caching server.  I think it just relays 
queries to upstream servers, which in your case are still unreachable, and 
will still cause asterisk to timeout waiting for a reply.

You need a true local DNS server that can answer for your asterisk box and 
any named phones.  A caching server should do also, assuming that your 
link is up long enough to serve and cache a few local queries before it 
goes down - pretty much how most of my systems run.

j