[asterisk-users] asterisk fails when DNS or internet fails

[Hans Witvliet]

On Mon, 2011-05-30 at 23:15 -0400, Jeff LaCoursiere wrote:
> 
> On Mon, 30 May 2011, Sherwood McGowan wrote:
> 
> > True, but with all due respect, if the cache's TTL expires and the OP's 
> > PBX cannot reach an external DNS server, they have bigger problems ;-)
> > 
> > Slainte all!
> > The Mick
> >
> 
> I couldn't disagree more.  In fact I think this problem is more serious 
> than it is getting credit for, when asterisk is in use in places where 
> Internet connectivity is far from stable.  I have several hotels that have 
> gone without Internet connectivity for days, and somewhere between one and 
> three days down they can only spottily call within the system, and can't 
> make outbound calls on their voice T1.  Its certainly true that they were 
> suffering without Internet access, but it is very hard to explain to the 
> owners why they can't use their phones.  In fact the symptoms are very 
> strange - inbound calls on the T1 get the auto-attendant, but internal 
> transfers fail.  No one can call outbound, and only *sometimes* do 
> internal extension to extension calls fail.
> 
> I still scratch my head about what exactly asterisk is trying to lookup 
> that keeps it from being able to place internal SIP calls from extension 
> to extension, and sadly the few times this has occurred I wasn't around to 
> debug.
> 
> Hasn't anyone managed to solve this with something better than a caching 
> DNS server, which seems to only last a short while?  What exactly is going 
> on that is failing?
> 

What kind of info is it about?
If it is the hostname of _local_ machines/clients, you should be
authoritive. That should keep asterisk happy.
If it is about remote nodes, well if your isp-connection is lost, you
can not contact them anyway ;-(

So run locally your bind-server, authoritive for your own addresses, and
caching for external ones.

hw