On Fri, Dec 15, 2000 at 10:39:56AM -0800, Bill Studenmund wrote:

> You might also look into trying to add the VMAC address as a multicast
> address on that network interface, rather than putting it into promiscuous
> mode. There is a check in ether_addmulti() making sure that the MAC in
> question is actually a multicast MAC which you'd have to circumvent. But
> if you used AF_UNSPEC for specifying the address, you probably could pull
> this off. You would then not have to use promiscuous mode - the only
> packets which would get passed into the kernel would be ones for either
> the real MAC or the VMAC.

Hm. Let me partially disagree:

some chips have seperate "listen-to-multiple-multicast-addresses" and
"listen to multiple-unicast-adresses" lists (and flags to enable them). 
I don't remember offhand which chip it was... I looked at hardware docs
of RT8019, i82595TX and cswhatwasit (the one in the Shark, driver "cs")
in the last two years, so I guess it was one of them.

The implication is that some of the drivers would need additional support
for this. Some others will refuse to put unicast addresses into the multicast
filter. 

Regards,
	-is