On Wed, Mar 17, 2004 at 10:54:29AM -0600, Don Foy wrote:
> Running Ethereal in X11 on Mac OS X 10.3.3. When I go to capture and tell it
> to start, no interfaces are shown in the interface window. I can manually
> enter the interface (en0), but it then returns this error:
>
> The capture session could not be initiated ((no devices found) /dev/bpf0:
> Permission denied). Please check to make sure you have sufficient
> permissions, and that you have the proper interface or pipe specified.
On systems with BPF (e.g., BSDs such as Mac OS X), you need read
permission on the BPF devices in order to capture traffic.
This means you either need to
1) run Ethereal (or tcpdump, or any other program that captures
traffic) as root
or
2) arrange that you have read permission on the BPF devices.
Either of those will require you to use the sudo command; for 1) you'd
use "sudo" to run Ethereal (or tcpdump, or...), and, for 2, you'd do
sudo chown {your login name} /dev/bpf*
where "{your login name}" is the name you use when logging in.
Note that the "sudo chown" must be done after every reboot; the result
of that command will persist until the machine is rebooted, but will not
persist after reboots.