Get all possible servers on a LAN network

I'm using the details on connecting to a server from a client here: http://www.egghead开发者_C百科cafe.com/articles/20020323.asp

It's quite out dated but I just need it for a quick project. I need the client to auto-connect. This program will be running on the LAN only, is there a way to find on what computer the server is running on (i.e. all computers hosting the specific server on port x). I've seen it on a couple of games that run on LAN. Without access to the internet, they manage to display all available games on the local LAN. I'm doing this with VB.net.

Thanks!

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IF you make all your clients/servers listen on a specific UDP port you can just multicast on that UDP port and get an answer from the server(s)... OR the server just muticasts on that port in a spcific interval (i.e. once every minute/10 sec...)... this way you know the server and if need be all clients on the LAN... a UDP multicast doesn't leave the LAN since the usual routers/firewalls would need to be explicitly configured to allow UDP multicast packet to leave the LAN...

some reference links including VB.NET source code:

• http://msdn.microsoft.com/en-us/library/system.net.sockets.udpclient.aspx
• http://www.dotnet247.com/247reference/a.aspx?u=http://www.knowdotnet.com/articles/udpbroadcastmessage.html
• http://www.eggheadcafe.com/articles/20040126.asp