org.wireshark.Wireshark
Wireshark allows you to examine protocol data stored in files. It supports dozens of protocol capture file formats and understands more than a thousand protocols.
It has many powerful features including a rich display filter language and the ability to reassemble multiple protocol packets in order to, for example, view a complete TCP stream, save the contents of a file which was transferred over HTTP or CIFS, or play back an RTP audio stream.
NOTE: This version of Wireshark does not support capturing data.
Latest reviews
Fail to open due to error "flatpak-org.wireshark.Wireshark-21301.scope: Failed to add PIDs to scope's control group: Permission denied". Apply work-around "systemd.legacy_systemd_cgroup_controller=1" in boot parameter, but face other error: "kernel: [ 79.453863] traps: bwrap[5036] general protection ip:xxxxxxxxxxxx sp:yyyyyyyyyyyy error:0 in libc-2.27.so[7f5f11af7000+1e7000]"
Wireshark is, in my opinion, an excellent tool for troubleshooting network issues. Flathub's packaging of the app works as expected. The install was simple and the resulting application works the same as it does on other platforms.