Duplicate MAC Addresses

I was sitting around talking the other day, and the topic of spoofing MACs somehow came up. (Most *nix systems allow this to be done, provided the physical interface allows it.)

I started to wonder something, but I'm hesitant to try it, especially since I'm on the campus LAN here, rather than a smal LAN I control, so screwing it up wouldn't go over well. Duplicate MAC Addresses

What happens if two systems on the same LAN segment have the same MAC address? Everything's built with the assumption that this can't happen, but it's possible to do it in software. Will a switch get royally screwed up if it's seeing the same MAC on two different ports? Does it just go by whoever it sees first? Last? Send it out to both ports? Burst into flames?

Has anyone tried this before? I'd try it, but I don't have a private little network of my own right now, and am assuming that the network people on campus might not be very happy if my box starts advertising the same MAC as one of their systems. Duplicate MAC Addresses

 

 

 

 

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