What are you using to find the server. Matchmaking? Simple Server search?
There are a few different sets of servers that can be retrieved:
Internet server list - game servers hosted on and accessible via the public Internet
LAN server list - game servers found on the local class C network via UDP broadcast
Friends server list - game servers where your friends are currently playing
Favorites server list - game servers that the current user has explicitly marked as a favorite
History server list - game servers that the current user has played on recently
Spectator server list - game servers marked in a special 'spectate' mode, which means they are actually a proxy that allows the user to observe a different multi-player game via a relay.
You can query servers from steam in many different ways. (Filter by geo) etc…