We seemed to be having this problems also, I will list some things that we did that might help people solve this problem. The prime symptom seems to be that everyone can start the server, and it seems to just stop at the "VAC secure mode is activated" and you cant see it in the internet tab, but you can either through adding it directly to your favorites, or over your LAN.
All of these are using your LOCAL IP!!! ie. 192.168.x.x!! or for static ips 192.168.x.xxx you do not need your external ip!
1.I feel a little odd saying this but if you have a dedicated server running on your network, you cant find it on the internet if you are on the same local network. In other words if you are connected to the internet through the same router as you dedicated server, it disables the ability to see your server in the internet tab.
2. Make sure you setup your static ip right follow this guide
http://www.portforward.com/networking/staticip.htm
just use the xp tutorial and there shouldn't be much thinking involved to input it correctly into your Linux platform.
3.On our router setup we made sure that all the port forwarding was going to the correct static ip (you need a static for port forwarding) we just port forwarded 80-30000 (just to make it easy) we did this for both TCP and UDP packet protocols, then we added the same for the port triggering (probably don't have to but its just less the computer has to work through)
4.Set up the DMZ to point at your static ip of the dedicated server that is about all you do (this should void all need of port forwarding but we just did it to make it easier for the computer to connect)
5.Time- you might need to wait a while for steam to register your server, i would suggest that you start your server, check to see that nothing critical failed, and go to sleep. When u wake up, check it, if you are lucky someone logged on, you will most likely see something about steam challenging ip (or something to that effect) i believe this is steam making the rounds to make sure the server is still running and connected.
In summary, you cannot see your dedicated linux server on the internet if you are in the same local area network!!!(all connected to the same router or internet box ((dsl/cable) If really want to know, ask a friend on steam (who is not connected your your local network) to try to find the server and login. I HOPE THIS HELPS SOMEONE.. please reply with any questions or corrections. THANKS!