Steam Games Multiplayer

Hi

I've had this problem with my friends for a long time and it's that whenever we try and host a game on any steam game no one can join or see the server. If we try and join the server via their name from the friends menu it just says server not responding. If we try to join via the console and the host's IP it also fails.
We've tried opening all the ports on our routers shutting down all your firewalls/antiviruses with still no hope. We have also tried hamachi and it does not seem to appear in our LAN games either.
It only effects games in steam cos we downloaded halo trial just as a test and it works perfectly without a problem, and anyone can host a server and people can join. We have also tried shadowrun and it works fine aswell.

Dedicated servers that are setup by us also do not work and none of us can join even a person that is on the same internet connection as the host (his brother).

What we suspect the problem is something to do with steam hosting the game with our LAN IP and not our internet IP which causes us to see the server as not responding or unable to connect.

The games with have are...
1) TF2
2) CS: S
3) HL2 DM
4) synergy
5) Gmod
6) Red Orchestra
and many more but these are the ones we usually play.

So can you guys think of what the problem is? and any idea how to solve this problem?

Thanks ^^

 

When I hosted a small server if someone else wanted to connect to it they had to type my internet IP along with whatever the default port number was.

Use this to find your IP:

http://www.ip-adress.com/

 

Open the console, type sv_lan 0

Then go to www.ipchicken.com get the IP, and give it to people who are going to be joining the server. All steam LISTEN servers from in game start in LAN mode.