Solved 3cx switches to IPv6 and breaks the trunk

[mhkdk]

My trunk with the registrar "sip.easybell.de" worked without problems since I started using the Hosted by 3cx solution. Yesterday at 3 am (CEST), within the 3cx update window, it stopped working with the error:

Call or Registration to [Name of the trunk] failed.
sip:[email protected] replied: 403 IP not allowed; from IP:2001:4090:4008::173:5060 [-> this is the IPv6 for the domain sip.easybell.de]

I was able to resolve the issue by setting the registrar in the trunk to the IPv4 address of Easybell instead of using their domain. At Easybell the trunk is configured so that a connection requires Username/Password and a trusted IP (they only support IPv4). It worked perfectly fine until the 3cx decided to switch to IPv6 and therefore Easybell blocked the connection. Normally, I could just disable IPv6 in the network settings, but they are not available in the "Hosted by 3cx" solution. Even if Easybell would support a trusted IPv6, I can't find the public IPv6 3cx is using anywhere in the dashboard.

I've already read in other threads that you recommend not using a trusted IP scenario, but I like the improved security and hope, you can enable the setting to not use IPv6 for your hosted solution.

 

[NikosT_3CX]

@mhkdk can you PM me with your license key ?

 

[YiannisH_3CX]

Hello @mhkdk

I checked the Easybell customer portal and i could not find any IP restrictions so that should not be an issue but you could always switch your trunk registration to IPv4.
Please navigate to your trunk settings / Options and switch the IP mode to IPv4. That will force the PBX to register via IPv4. Make sure you are using the Easybell default template with the default registrar.

 

[YiannisH_3CX]

Additionally to the above it is recommended to not limit your IP with your provider to prevent downtime while you try to whitelist your new IP.