Eclipse TCP/IP Monitor has two ports

Question

I was trying to monitor request using TCP/IP Monitor.

But, I see there are two ports which are in use. One is the application port[8080] and other monitoring port[9833].

Can anybody tell , why there are two different ports?

When I launch the application it launches at 9833 instead of 8080. Why this change?

Answer 1

Eclipse monitoring is done by capturing all the requests sent to an application (a host and a port), dumping it on the Monitor console for you, then forwarding the original request to the application. The monitored application itself will return its responses to eclipse (where it is the client from its prospective) where eclipse dumps it on the monitoring console too.

Now, how does eclipse captures the requests sent to the monitored application at the first place? it simply runs a service that accepts these requests (on behalf of the application) and forward it, this service also returns the application responses to the original requester.

Based on the above, in eclipse TCP/IP Monitor screen, the Local monitoring port is the port of the eclipse service (which you can use any available port number for), and the other Port is the monitored application port number.

So, in your case, the application you are monitoring is running on port 8080 and eclipse service is using the port 9833 (which is just a random port that you can change).

Your application port have not been changed, it still runs on 8080 and you can try that, but no data will be captured by eclipse TCP/IP monitor unless you use the port 9833.