*Hi, I wrote a client/server programs, the server listen on port 5000 and of course the client connected on that port , I check the communication via the sniffex.c program from pcap (adapting something) , I noticed that destination port ( used by the client) is not always the same and completely different from the source port. Here is an output example:
Device: lo Filter expression: ip Packet number 1: From: 127.0.0.1 To: 127.0.0.1 Protocol: TCP ---->The client send a request Src port: 49611 ---->The port is randomly choosed by the client ?? Dst port: 5000 Packet number 2: From: 127.0.0.1 To: 127.0.0.1 Protocol: TCP -----------> The answer from the server Src port: 5000 Dst port: 49611 When I stopped the client and ran it again I got another Src port from the client The question is : why the port opened by the client is not the same, and takes one randomly ?? thanks for help *