Hi Sandeep, i didn't see where you said if these hosts you want to ping are on your internal network, or beyond your gateway. Probably the only truly reliable way to maintain an active hosts list is to install a ping-sending client on them, like
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52302 And think about possible legal ramifications of port scanning hosts or possibly getting your IP blacklisted by a host's firewall, before you do it. -- http://mail.python.org/mailman/listinfo/python-list
