"Start Multiplayer" option doesn't work online

Hi there! I recently bought GMod (during that CS:S summer discount). Two of my friends also did so we could play together, but we can’t use the multiplayer option. When we use it, we start the game as usual and we can play alone (like singlepayer), but the others can’t join. I don’t know if this is normal, but any of us can make it work. Is the multiplayer option made for online gaming or just LAN gaming?

Everytime we use the Steam Interface to join, we get a “server doesn’t answer”. How can we do to play in multiplayer without joining a server? Could we play with our own maps and models?

I’m new at this and I don’t know anything about GMod servers, I’m sorry.

Thanks!

you can host a server without port forwarding

I suggest you join a server hosted by someone else

Then, if I want to make a server to play a X map with my friends, I need to make a dedicated server, right? I heard that it’s very laggy.

The simplest solution to me is probably just to use hamachi or some sort of program like that if you can’t port forward.

I tried to port forward. I opened from 27000 to 27050 and 1200, on firewall and router, but I still get the same “connection failed after 4 retries” or “server not responding”. I think I will download Hamachi or something.

Did you also forward those ports on the firewall of your pc?

I tried to open from port 27000 to port 27050 and 1200, in my firewall options and my router. My firewall detected something when I opened my GMod (I allowed it), so I think the problem is the router, if it’s it.
I tried with some friends yesterday but my listen server didn’t work. We tried with the Steam join feature and the “connect” command, but we got the “server not responding” and “connection failed after 4 retries”. Maybe I should talk with my ISP or trying to force some friend to open his ports.h

EDIT: Okay, I made it work, but I need to shut down the entire COMODO firewall (and I don’t like that). I try ti configure it, but I can’t. Maybe I should ask on their forums.