The TCP option

What is Ping plotter looking for when it is using the tcp session packet option. An ACK or a RST (reset). If the destination is not listening on the selected tcp port and sends a RST is that treated any different than using tcp 80 to a real web site where the server will reply back with a ACK.

Also is each session set up with the final SynAck is it also ended with a Fin?

Hi, Jim.

Thanks for the question!

We look for any ICMP reply or an ACK. We do not look for a RST packet at all.

After we get an ACK, a RST is sent back. We do *not* send a FIN.

We're always looking for feedback on the methods we use, so please feel free to comment if you don't think this is appropriate.

Best wishes,
Pete

It could be useful to watch for a RST. It would allow for testing to a server that is not thrilled with talking to a test tool.

We have a case where a service is not designed to talk with many clients. Instead it only talks to one client on one fixed port. If the same client trys to establish a 2nd session it is refused. RST

This keeps us from being able to run PingPlot on the client to the server on the same port that we use for the production session. Two firewalls prevent use of other ports. We have asked for ICMP access for testing but the provider is reluctant.

Other wise would would say that I love Ping Plotter and was pleased to see it got a nod from NetworkWord (Mark Gibbs)