[c-nsp] vc ipv6 dhcp ssm packet

Lukasz Bromirski lukasz at bromirski.net
Sat Feb 8 10:09:06 EST 2014

On 08 Feb 2014, at 08:54, Arne Larsen / Region Nordjylland <arla at rn.dk> wrote:

> Hi all.
> We are having a problem with Windows DHCPv6 SSM multicast packets on our network.
> We aren't running ipv6 or multicast, so all SSM packets are sent to the processor on the 6500 which is a sup720-3B with a pfc3b cards
> This makes the load on the cpu very high.
> We are running s72033-ipservicesk9_wan-mz.122-18.SXF13.bin on one box and
> s72033-adventerprisek9_wan-mz.122-33.SXJ2.bin on the other.
> Can someone give me a hint how to get around this.

First of all - update the IOS, as those versions are way old (but this
is not directly connected to the problem you’re seeing).

Next, try to configure multicast defence with mls rate-limit - the
specific values should be tuned to your network. Start here and then
follow up to the configuration guides:


"There's no sense in being precise when |               Łukasz Bromirski
 you don't know what you're talking     |      jid:lbromirski at jabber.org
 about."               John von Neumann |    http://lukasz.bromirski.net

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