The simple way how to start Wireshark on Linux is to type:
wireshark
If you run this command as a normal user you won’t be able to capture packets. In order to dump packets, you need to execute it as root. This must be done in a specific way. If try just sudo you’ll end up with interesting errors like:
Attempt #1
$ sudo su # wireshark QXcbConnection: Could not connect to display Aborted (core dumped)
Attempt #2
$ sudo wireshark QXcbConnection: Could not connect to display [1] 8836 abort sudo wireshark
The proper way how to start Wireshark is by gtk-su:
xdg-su -c wireshark