Originally Posted by fourthdimension
First, is it a direct connection? I'm assuming by the chat system you mean something similar to IM. What OS are you running? If this is all done through a web browser, it you have a very low probability of being able to get their IP. If it's done through a conventional chat window, then you shouldn't have too much trouble.
Until I know more, I can only give you the general idea of what you need to do. You need to initiate some sort of direct connection between your computers (so that you don't get the IP address of the relay server), perhaps via a file transfer if it's not already a direct connection, then run a network sniffer/monitor such as etherape, which will give you all the IP's your computer is connected to. Watch for the one who's activity spikes while you transfer the file or chat.
thanks for ur suggestion but i was looking for is to sniff the chatters ip in the room spc in java chat room .so without having direct connection is their any alternative solution as the chat site i was reffering doent allow the person to transfer pic or file it allows only public message or im made by java .and i guess this java are really tough to handle as they know the real ip of mine so i use vpn to connect this room.any alternative methoad to sniff ip pleaseeeeeeee