Mumble: Why is my forwarded port reported as closed from canyouseeme.org?

I have set my router to forward the port for Mumble to my server machine on the LAN.

External site (and Mumble users trying to connect to my client) report failure:

I can connect to the Mumble server on the LAN without issue. I have restarted the router. Have I set up the mapping incorrectly, or is there an issue with the Mumble server on 16.04?

Edit: I suspect my ISP may be blocking the port, since it's a SIM based network.

1 Answer

run netstat -an | grep 64738 to make sure the service is listening on 0.0.0.0 and NOT on 127.x.x.x