World IPv6 Only Day.

TJ trejrco at
Thu Jun 9 18:56:45 UTC 2011

On Thu, Jun 9, 2011 at 13:34, Ray Soucy <rps at> wrote:

> Cisco has had MLD snooping support for some time.  But they seem to
> have broken it in a recent release, so it drops ND traffic and breaks
> IPv6; been after them to fix it, but doesn't look like it's been
> resolved yet.
> But you're correct that without MLD snooping IPv6 ND traffic is on par
> with IPv4 broadcast traffic and not a major problem.  <snip>

While I certainly agree it is not a major problem, it should be _even less_
of a problem than ARP.  Yes, the non-MLD-snooping switch forwards all
multicast to every port - but the other end of those cables (the nodes
plugged in to the switch) don't need to process the frame at all - not
listening for that MAC.  Compared to ARP, where the frame is picked up and
handed to layer3/IPv4 before being discarded.


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