you can't determine conclusively whether a port is 'open' from a remote location. what actions does your CPU take when bits arrive on an exposed network interface? If you don't know, then you can't tell whether a port is open. judging a port to be 'open' because it responds to the TCP 3-way handshake and 'closed' otherwise is wrong, even if you only care about TCP and ignore UDP.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, August 07, 2003 7:45 AM To: [EMAIL PROTECTED] Subject: verifying an open or closed port on an ip address Hello, I am looking for a windows compatible utility or method, preferably command line, where I can verify whether a port on an ip address is reachable or not. I want to be able to do individual ports and not port scans. Say for instance I wish to verify that port 677 is closed to traffic on ip address Ex. 172.16.0.1, I'm looking for a utility that would do something like: Check 172.16.0.1 port 677 and tell me whether that port was reachable. So if I have two networks and I use this command from one I can determine whether a port is reachable on another. To determine whether a security measure is failing or not. There may be a simple way to do this... Thanks Ian :) Go to www.missingkids.com But give an' take's the gospel, an' we'll call the bargain fair, For if you 'ave lost more than us, you crumpled up the square! Mowgli's real Father... --------------------------------------------------------------------------- ---------------------------------------------------------------------------- --------------------------------------------------------------------------- ----------------------------------------------------------------------------
