promiscuous mode, was Re: [HECnet] Multinet Tunnel Connections to SG1::

On 06/07/2012 08:16 AM, Johnny Billquist wrote: Any program that needs access to raw ethernet packets needs to run as root. Promiscuous mode or not. Promiscuous mode itself has little to do with this. So if you want to run anything like a bridge or a router, you will need to run it as root. Promiscuous mode is basically just allowing you to share the same interface as the system is otherwise using, instead of having to dedicate a separate ethernet interface for this. Maybe you're just putting this another way, but promiscuous mode is correctly defined a bit differently than this. When an Ethernet controller is placed into promiscuous mode, its on-chip MAC address filters, which normally either select or ignore inbound packets based on their MAC address, are disabled. ALL packets are received by the hardware and passed to the Ethernet driver in the OS, rather than only the ones destined for that specific interface as defined by its MAC address. I'm reasonably certain that you know this but were just explaining it in a more abstract way...? -Dave -- Dave McGuire, AK4HZ New Kensington, PA