[f-nsp] Multicast causing high CPU

[Niels Bakker]

* christian.macnevin at gmail.com (Christian MacNevin) [Tue 19 Aug 2008, 19:16 CEST]:
> I've got a customer who's seeing very high CPU utilisation whenever 
> multicast is turned on across his BigIrons. I'm sorry I can't be more 
> specific than this, it's just about all the info I have.

Assuming that with BigIron you mean IronCore or JetCore - these forward 
multicast over the CPU by default.  On Jetcore you can enable hardware 
flooding of broadcast/multicast on a per-VLAN basis or in later software 
releases with the cpupro command based on recent average CPU load.


> They also have cisco 3750s and 65s which seem to be doing fine. Before 
> I can get a chance to look at the topology, I'm thinking about maybe 
> rpf checking owing to a split l2/l3 architecture, or possibly just the 
> RP functionality being too much for it (decapsulating PIM registers).

That's definitely going over the CPU, I'm not sure that h/w flooding 
will even help you...


> Are there many multicsat users on this list? And for that matter, are 
> there any good high cpu utilization troubleshooting guides out there 
> for foundry?

For a six to ten year old platform?


	-- Niels.

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