[c-nsp] Sup720, multicast bothers the CPU

[Peter Rathlev]

On Wed, 2011-03-23 at 09:04 +0000, Phil Mayers wrote:
> If you just want to drop all multicast, you could try:
> 
> int VlanXX
>   ip multicast boundary MULTICAST-drop
> ip access-list standard MULTICAST-in
>   deny 224.0.0.0 15.255.255.255

Would that also discard forwarding of multicast packets L2-wise? Or only
L3-wise?

> Is the sender attached directly to a port on the 6500? There are some 
> newer features related to layer2 (as opposed to layer3) multicast ACLs 
> in SXH/SXI.

The devices in question are not directly connected, but some might be in
the future.

> > The box in question does not have any multicast configuration at all.
> > Does this mean all multicast traffic is sent to the CPU? How would one
> > configure a Sup720 to not punt every multicast packet to the CPU?
> 
> There are also mls rate-limiters for this, but I'm not sure off the top 
> of my head which one you want - we have multicast configured so don't 
> need them (the box builds hardware mfib entries, which stops the CPU punts)

That has me interested: What can I configure to make the traffic
hardware swithed? Is it as simple as an IGMP querier or something like
that?

-- 
Peter