Solved SIP Trunk Suddenly not registering

[McDowellster]

Hello,

I have four SIP trunks on my self hosted 3CX instance. It's been running for YEARS without issue. Its updated to the most recent v18 build.

Just ONE of the SIP trunks suddenly will not register... Last success was on April 10th 2022. ALL other SIP trunks are fine. Work after a reboot / etc..

Troubleshooting:
Replaced DNS name with IP
Opened the box up COMPLETELY to the internet
Moved to different host virtual host
No firewall traffic appearing when attempting to connect outbound from 3CX
NetCat attempts SHOWS 5060 is open on the other side AND firewall shows traffic.
Called SIP provider (of course nothing is wrong on their end)
Tested account on a softphone, worked fine...!

GUI Logs:

• Registration at Acanac has failed. Destination (sip:206.80.254.101:5060;lr) is not reachable, DNS error resolving FQDN, or service is not available.
  SIP Server ID: 12293 05/02/2022 1:41:28 PM
• Registration at Acanac has failed. Destination (sip:206.80.254.101;lr) is not reachable, DNS error resolving FQDN, or service is not available.
  SIP Server ID: 12293 05/02/2022 1:38:56 PM

Support Tool Logs:
02-05-2022 13:32:16:641 | 9 | [CM504005]: Registration failed for: Lc:10000(@Acanac[<sip:[email protected]:5060/UDP>]); Cause: Cause: 408 Request Timeout/REGISTER from local
02-05-2022 13:33:52:420 | 9 | [CM504005]: Registration failed for: Lc:10000(@Acanac[<sip:[email protected]:5060/UDP>]); Cause: Cause: 408 Request Timeout/REGISTER from local
02-05-2022 13:36:24:569 | 9 | [CM504005]: Registration failed for: Lc:10000(@Acanac[<sip:[email protected]:5060/UDP>]); Cause: Cause: 408 Request Timeout/REGISTER from local
02-05-2022 13:38:56:709 | 9 | [CM504005]: Registration failed for: Lc:10000(@Acanac[<sip:[email protected]:5060/UDP>]); Cause: Cause: 408 Request Timeout/REGISTER from local
02-05-2022 13:41:28:840 | 9 | [CM504005]: Registration failed for: Lc:10000(@Acanac[<sip:[email protected]:5060/UDP>]); Cause: Cause: 408 Request Timeout/REGISTER from local

HELP!

 

[cobaltit]

Is the trunk IP blacklisted?

 

[McDowellster]

I don't see any blacklisted IPs on my instance at all

 

[cobaltit]

Get a list of IPs from the provider and whitelist them. If they got on the 3CX blacklist it wouldn't show.

 

[McDowellster]

OMG.

Why isn't this posted more publicly. INSTANTLY fixed it.

at the VERY LEAST the errors in the log should show its a blacklisted IP

 

[cobaltit]

Well I assume you aren't using a supported provider as those are whitelisted automatically (although some have gotten blacklisted briefly). But as a SOP we whitelist all provider IPs because it's silly not to.