Unable to access dedicated server from host network

If you have a server and a client behind the same router and the router has NAT enabled, you will not be able to connect your client to your server using the external IP address.

This means you will not be able to connect to the Server by just clicking on it in the Steam ServerBrowser window.

In fact, you probably will not be able to see your Server in the Steam ServerBrowser Window or in the Steam LAN Serverbrowser window.

You must use the internal IP address and port.

What you do is go to:

Steam > Servers > Favorites then add your internal Server IP and port

For example, if 192.168.1.100:27015 is what your Server says when you type in "Status" in the Server console then that is the address and port that you must add to your favorites.

Then you should be able to connect to your server from the favorites menu.

People on the outside still connect using your external IP address and port.