Stephen Hemminger [off-list ref] wrote on 06/04/2013 
12:00:31 PM:

I am still not 100% convinced of the use case of providing multiple 
destinations.
It seems like either a solution for migrating guests, a way to do 
SPAN, or a weird
form of multicast.

The use is, as you would say it, a weird form of multicast. It
is to allow forwarding MAC multicasts without relying on the
underlying network having multicast routers in the same domain.
 

Wouldn't it be better to use something like TC actions for these 
special cases and
handle it at the IP layer rather than having to add so much 
complexity into the
VXLAN driver itself.

This isn't a "special case" for DOVE -- it is the mechanism
for doing MAC multicasts. I don't agree that the code is
complex -- it simply replaces what was a vxlan_rdst with a
list of vxlan_rdsts. And, no, I don't believe it can be
done with equivalent performance using external mechanisms.

Didn't we have this discussion when the patch went in?

                                                        +-DLS