hey … is there any posibilities tat i could run server and client locally and test out with no problem but when i try out using 2 computers, then problem occurs??
You're probably using InetAddress.getLocalHost() and it will reference 127.0.0.1 instead of your actual network address. Try using null instead for the host and see if that works.
actually i have problem with firewall … is that a must that i have to turn off my firewall everytime i run my game?
Depends on port configuration and how your firewall is handling connections. Like any game you often have to either use UDP punch-through or connect outwardly from a client machine. Where you're probably having problems is perhaps your server exists on a home ISP that does allow inbound connections. This is where the major distinction between "client" and "server" comes into play and also why I think P2P can be really problematic.
hmmmm … thankz for that … 