You don't. The searching for server function is just listening for multicast announcements from servers that are making such announcements. It isn't really "doing" anything. In another thread someone said that they had figured out how to make an announcement for their server that would propagate over the WAN. I'm not sure how reliable that would be (i.e. how much of the world / internet that would actually announce it too.). Plus an "open to LAN" server re-announces quite frequently (multiple times a minute). That obviously wouldn't scale to having WAN servers send announcements around the world.