ppp0 mac address?

Martijn van Oosterhout kleptog at svana.org
Tue Jul 16 17:36:03 EST 2002

On Tue, Jul 16, 2002 at 04:33:24PM +1000, Michael Still wrote:
> for 10 second intervals. This works fine on my wireless network. Anyway,
> when I run this against ppp0 I seem to get incrementing mac addresses. An
> ipconfig for ppp0 doesn't even show a mac address. I understand that mac
> addresses are an ethernet concept only.
> Anyway, my question is: are mac addresses emulated for ppp0? If so, why do
> mine keep changing?

Perhaps you should get libpcap to tell you the datalink type. If it's
ethernet, then you can apply the eth_hdr structure to get the MAC address.
However, on a PPP link it returns DLT_RAW or DLT_PPP or something like that.
You're probably getting some packet counter or something and interpreting it
as a MAC address.

Look through the headers for something that looks like a PPP wire
Martijn van Oosterhout   <kleptog at svana.org>   http://svana.org/kleptog/
> There are 10 kinds of people in the world, those that can do binary
> arithmetic and those that can't.

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