Conflicts with TCP Ports

mr_fern · 02-06-2006, 01:34 PM

If you have two pieces of software both configured to listen to the same ports (and same ip addresses), what happens?

Does the first one that run actually listen to that port and the second program gets ignored?

Does the second program run listen and the first one get ignored?

Do both programs try to listen to the port?

or Does the second program not even run due to port conflict?

bulliver · 02-06-2006, 01:46 PM

When you start the second server you should get:

SocketError: unable to bind to port

gilead · 02-06-2006, 01:47 PM

The first one running gets the port and the second one times out/errors. At least that's what happened on one of my boxes when Tomcat took port 8080 and another web server timed out waiting for it. Two programs can't listen on one port and if it were easy to bump an already listening daemon off with a second one, that sounds like an exploitable attack method.

mr_fern · 02-06-2006, 01:57 PM

Thank you both for quick responses.

Just wanted to make sure the first daemon wouldn't be affected.