Many new Wireshark users on Mac OS X run into an issue where no interfaces show up when trying to begin packet capture. If you attempt to manually input an interface (such as en0) this error will occur:

The capture session could not be initiated ((no devices found) /dev/bpf0: Permission denied).

To have the interfaces show up properly you’ll need to widen the permissions on the Berkeley packet filter (BPF). By default they look like this:

crw-------  1 root  wheel   23,   0 Jan 31 13:47 /dev/bpf0

We need the filter to be readable by non-root, so open Terminal.app and run this command:

sudo chmod 644 /dev/bpf*

Unfortunately every time you reboot this will More >