hi , plz help me from this. I am developing a multi chat application using Datagram.Here i used net view command(using exec method) to get the IP machines connected in the domain. from that established the communication. problem is what if any system in the network is shutdown my program give an exception unknownHostException.I need help for any of these either give me a command like net view that only shows the running system in the network. or to neglect the exception thrown. plz help me thanx in advance.