>>I'm not sure. It would add an ether_cmp() to a criticial path, but unlike
>>the smc91cxx.c case not only in promiscuous mode. Maybe it should only check
>>that if we are in half-duplex mode?
>>
>>But on the other hand, the current solution does not cause any performance
>>hit and works - what's the problem with it?
>
>	the problem is that !IFF_SIMPLEX interfaces are not really supported in
>	L3 logic.  we need to look at that (IPv4/v6 multicast, IPv6 ND, and
>	such).  i don't think i can make IPv6 DAD work with !IFF_SIMPLEX
>	interfaces, due to the way IPv6 DAD is specified.

	and i'm not sure if it is ok for a interface to change
	IFF_SIMPLEX <-> !IFF_SIMPLEX dynamically.

itojun