I just started a server yesterday running off my own computer. I have a port made with my Ip and both my external and internal ports are 28015 (default), I can join my own server and use all the mods but when I give a friend my public Ip to connect with he starts loading in and it times him out. And I don't have a modern, I've used the port checker and It doesn't find it and I've just run out of ideas and I'm looking for help, thank you.
Port Forwarding Picture

.bat file

You need to open the port in your firewall.

Merged post

On your screenshot you say "my IPV4 address" - that should be your internal IP, it's usually 192 168 x x

Thank you for the quick response, that did it!