Configuring TURN Server for Mattermost Calls

Troubleshooting
10

Ok, I’ll try to clarify:

Yesterday, I only tested your new proposal:

  1. I removed the previous stun/turn server configuration, so this config text box was empty.
  2. I entered my Mattermost host name (without protocol part and without port specifier) into ICE Host Override.
  3. I stopped and re-started the plugin.

After it didn’t work on the first attempt when my colleague still had VPN enabled, we tried without VPN. However, there may be traces from attempts with VPN in the server logs.

Mattermost is reachable without VPN - we need VPN to access other internal IPv4 based services.

The reverse proxy in front of Mattermost is also reachable through both IPv4 and IPv6.

Mattermost itself was only listening on 127.0.0.1, i.e. IPv4 localhost, behind the reverse proxy. I now changed this to ::1 / IPv6 localhost, but don’t expect this to make a difference.

As far as I can interpret netstat, the Calls plugin seems to listen to IPv4 UDP only on all interfaces, before and now:

udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m 
udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m 
udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m 
udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m 
udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m 
udp        0      0 0.0.0.0:8443            0.0.0.0:*                           25297/plugins/com.m

I’d have expected it to listen to [::]:8443, at least additionally, but that does not seem to be the case.

Host OS is still Debian 10 Buster, upgrade to Bullseye will happen soon.