How to intercept a packet?

Question

Computer networks

Hello, I wrote 2 client server applications.
1 client sends a string to the server without encrypting it
2 client sends a string to the server encrypting it
I want to check the operation of the program, but for this I need to somehow intercept packets that go to a specific port. That is, I need to somehow intercept messages from the client to the server.
Tell me what software do I need to install for this?
Thank you very much in advance!

Answer 1

tcpdump, wireshark