Getting Network Ip's [Read Thread For Extencice Description]

I wanted to add network code to my 'Mens Erger Je Niet' Game,
I just remembered that, with games like unreal, or command and conquer, you can see all servers in your network in a few seconds (i mean lan servers here), do you guys know a way of finding LAN computers with a specified open port (listening network game)?

I would really like to know, thanx in advance.

just a trick : you have to send a broadcast packet (which is 255.255.255.255) plus your port by ex : 2750

then when your server will receive your packet then they will send you their ip adress...
it seems to be simple but.....

sorry 4 my english.

just a trick : you have to send a broadcast packet (which is 255.255.255.255) plus your port by ex : 2750

then when your server will receive your packet then they will send you their ip adress...
it seems to be simple but.....

sorry 4 my english.
Cool, thanx, never used broadcast messages b4 (checked the descriptions in the socket class to), so i think i will give this a go this weekend, thanx!