A guide to learn how to use wireshark is available in their website: https://www.wireshark.org/#learnWS
For some other guide, you will have to be more specific.
A guide to learn how to use wireshark is available in their website: https://www.wireshark.org/#learnWS
For some other guide, you will have to be more specific.
Wireshark is probably the best way.
https://www.wireshark.org/
Wireshark can show you traffic coming to the host it is running on. To monitor ALL traffic in an entire network is not something easily done with Wireshark. If you have Wireshark running on host A and hosts A, B, C are all connected to a switch, then Wireshark will never see traffic between B and C.
Another option is to use Microsoft' NetMon. You run it on the same computer where the application you are interested in is running, and I think there is an option to monitor just that app' traffic.
Edit: Are you trying to capture/crack registration / login / authentication info?