Can't join friends gmod server but used to

Randomly i cant join my friends dark rp server anymore, hes is in it but when i click join game it says server not responding.
I’ve also noticed his server ip is xxx:27016 instead of the normal xxx:27015. I was playing on the server for 2 days.

2 things to check for:

  • Is port 27015 port forwarded
  • Did your friend’s IP change
  • Is the IP you are connecting to a LAN IP (Ex: 192.168.x.x, 10.0.x.x)
  1. Yes
  2. No
  3. No

If it randomly stopped working, it might mean his ISP shut off his portforwarding automatically and he might have to re-enable it

His local IP must have changed