Lost registration connectivity with all phone and VoIP trunk

September 10, 2018 between 7:50AM and 9:59AM EDT, my FreePBX with the Asterisk version of 13.18.3 lost connectivity with the VoIP service provider and with all the extensions.

These error, warning and notice start to show up in the asterisk log (/var/log/asterisk/full) at 7:50AM.

ERROR[2401] netsock2.c: getaddrinfo("VOIPTRUNKPROVIDER", "(null)", ...): Temporary failure in name resolution
WARNING[2401] acl.c: Unable to lookup 'VOIPTRUNKPROVIDER'
NOTICE[2401] chan_sip.c: Peer '254' is now UNREACHABLE!  Last qualify: 325

This set of error, warning and notice keep repeating for 23 times and gone away completely at 9:59AM.
They come and go on their own.
No network connectivity issue was noticed any the time.
When the issue was happening, no incoming call nor outgoing call was successfully terminated.
Checked with the SIP trunk provider and they said they couldn’t find any fail registration at their end neither!

Does anyone have any idea of what this issue might be?

I am thinking could the lost of connectivity to the SIP trunk provider cause our server to also lose connection with the extensions.
If this was the case then I can just sign up for trunk service from another provider to use as fail over.

The error is indicative of a DNS failure.

You may want to run a caching DNS server and have your PBX use it for name resolution.

DNS look up failure is another possibility for why the server lost the registration to the VOIPTRUNKPROVIDER.
If this were the case, then it would the fault of the DNS server.
The thing which concerning me more is why the FreePBX also lost the connectivity with the office phone at the same time. Is this an expected behavior?

If the phone use a hostname to connect to the PBX then a DNS outage would cause the phones to go offline when they periodically reregister or attempt to originate a call.

If the PBX is configured with a hostname it may be attempting to look up its own name and fail as well.

I remember years a go a bug with Asterisk " Asterisk stops responding to SIP devices if it loses Internet Access (DNS) " but it was an older version of Asterisk but the symptomps where similar to the one you describe


The phones use the private IP address of the PBX server to register.

Do you know which version of Asterisk it was?

Open the link for the issue