[c-nsp] All multicast punting to CPU on 6500

Phil Mayers p.mayers at imperial.ac.uk
Mon Dec 17 08:34:21 EST 2012


On 17/12/12 13:32, Gert Doering wrote:
> Hi,
>
> On Mon, Dec 17, 2012 at 01:16:30PM +0000, Phil Mayers wrote:
>> I have a suspicion that re-using the IPv4/IPv6 multicast MAC OUI was
>> part of the problem - that is special-cased in a lot of kit,
>
> That's actually the brilliant thing about it :-) - and yes, kit that
> does not handle MAC-level multicast properly is broken, though usually
> there is not enough of that to actually notice.
>
> Wait for IPv6 ND flood attacks...  (and then nobody will be able to point
> a finger to MS to tell them "hey, all your fault!")

No need to wait. We've had several (accidental, but nevertheless). 
Suffice to say it had a... detrimental... affect on sup720 CPU usage.


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