SOLVED Internet Down = Extensions Down?

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I noticed this last night (and it happened Tuesday morning as well, but I wasn't home to see it so I didn't know what happened).

Both these nights Comcast has had outages (actually I could ping the comcast gateway but nothing past that, so not sure what they've been doing), and during these outages the majority of my extensions have gone offline. The server is in house, the extensions are in house, and the devices (and server) are perfectly accessible via hostnames/IPs (bind running on the firewall/router machine etc.), yet they lose registration.

Any suggestions?

Obviously I know the server loses the outside trunks, but the internal extensions should all stick work (and most of my outbound routes will failover to the POTS line so calls can still go).
 

rossiv

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This is being (somewhat) covered in another thread. It's a long-standing bug (or feature) in Asterisk. If you use DNS hostnames and it can't resolve them, Asterisk loses its brains. Many have tried just as many methods to circumvent the issue including running a DNS server on the server itself. Nothing is perfect though.
I don't recall who - maybe lgaetz - someone said earlier in the other thread that the issue has been fixed with pjsip in Asterisk 12.
 
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Huh..so basically, even though it should be using the LAN DNS server and can resolve all the local extensions fine (it shows the IPs in SIP Peers), the fact that it can't resolve the outside trunks is causing it to go haywire and determine that it can't route to the local extensions either?
 

rossiv

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I don't have a complete understanding of what happens, but something kills the entire SIP stack I think. As such it kills all calls. Could be wrong.
 
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From the post from tm1000 is appears that basically Asterisk is using a single threaded DNS lookup, and if it fails it apparently locks itself while retrying, breaking all SIP connections and that PJSIP is multi threaded so Asterisk won't lock itself up while retrying FQDNs that aren't currently resolving.
 

tm1000

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That is correct
From the post from tm1000 is appears that basically Asterisk is using a single threaded DNS lookup, and if it fails it apparently locks itself while retrying, breaking all SIP connections and that PJSIP is multi threaded so Asterisk won't lock itself up while retrying FQDNs that aren't currently resolving.
 

hbonath

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We run a caching DNS server on each of our PBXs with them pointing to themselves for DNS with forwarders enabled.
I can provide some configs for anyone that needs help setting this up.
 
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I did a little digging and found that apparently some newer versions of bind (like that on my firewall box) don't have caching accessible to other systems by default. I think I have my configuration fixed so the other LAN machines can actually use the cache now. Hopefully of course it will be quite a while until that is tested. :)
 

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