[nsp] Multicast Ghost

[Tony Wasson]

> Thanks Tony.
>
> We've enabled CGMP on the router's ethernet interfaces, and its on
> by default on the switches.
>
> We still see problems with two of our large sites though. However,
> one of these large sites has 2 4006s with the L3 card forming the core,
and
> the CPU was at 92% over 5 minutes.
>
> I tested this further today, with an office that had 2 2600 routers,
> 1 Frac T1 each, and there were no noticable impact to the network. The
> fas0/0 was taking in around 10-20mbps, and the CPU was at 60% over a 5
> second interval.
>
> I wonder if its a problem with process switching on the L3 card?

Rick,

What is your topology like? You aren't letting those pesky multicasts in on
the management VLAN are you? If the multicasts are in sc0 or me1 this will
cause high CPU utilization.

Just a thought,
Tony Wasson