Port Forwarding GMod

[Kaitan]

Could someone help me with forwarding ports for GMod? I do not know which ports to forward. My router is a Linksys WRT54GL, this may be helpful as some Router's settings are different. I am trying to port forward so people will see my server in the Internet tab of the server browser. Please help, I have done everything, but I don't think forwarding ports has worked for me.
Server OS: Windows 7 64-bit
Processor: AMD Phenom™ II X2 521 Processor (2 CPUs), ~3.5GHz
Ram: 6GB
Game(s): Garry's Mod
Start Up Command: C:\srcds\orangebox\srcds.exe -command update -game garrysmod -maxplayers 16 +sv_defaultgamemode "darkrp"
Admin Mods: ULX, ULib

[rawstyle]

You can read about portforwarding for that specific router of yours here:
http://portforward.com/english/routers/port_forwarding/Linksys/WRT54GL/WRT54GLindex.htm

Just choose what game you want to portforward.. Howeveer, I couldn't find gmod in it - maybe it's hl2 server or something?

I'm not any good for portforwarding, but you are lucky that yours is listed on that website. Good luck!

[Svenskunganka]

Portforward these ports:
TCP - 27015 (Not really neccesary if you don't want to use RCON)
UDP - 27015

and add "-port 27015" to the startup line.