I just want to make a server me and my friend can play in

I just want to play gm_ghost hunt with a friend. I don’t want to host a professional server for people every day. Just something for fun.

I have no problem doing this in Arma or any other game, why is this so damned difficult?

Help please

Check that the proper ports are unblocked (or forwarded), make sure that hl2.exe is allowed outbound and inbound traffic on your firewall.

Also, make sure you use your external IP Address