Perforce "Connect to server failed" when connecting to xxxxx.dyndns.org, but it works via 192.168.1.75

Question

So I've had a Perforce server running on my MacPro for several years. It is set to register itself as xxxxx.dyndns.org, so other users can connect from off my LAN.

Suddenly, today, I can no longer connect via xxxxx.dyndns.org:1666. I get an error:

Connect to server failed; check $P4PORT.
TCP connect to xxxxx.dyndns.org:1666 failed.
connect: some.ip.address.:1666: Connection refused

If I go to a bash shell and do ping xxxxx.dyndns.org, it comes up with some.ip.address and says it pings fine.

So if I can connect via the LAN IP address, and can ping the computer with the dyndns.org address, and the router is set to forward 1666 to the computer hosting the P4 server, what else could be wrong?

Answer 1

Got this answered. Note the use of dyndns.org up there. Their free services have been turned off. I rewired it to use duckdns.org and now it's working fine.