[nsp] Cat6509/MSFC2 hybrid, hw switched multicast forwarding

[Matti Saarinen]

c.spurgeon at mail.utexas.edu (Charles Spurgeon) writes:

> Our local SEs have been working with us, and they found an
> undocumented IGMP rate limiting command in the SUP2 under CatOS. You
> can see it with the CatOS command: "show igmp ratelimit info".

     That's useful information. Thanks.

> We currently have 40 PIM-enabled routers connected as a dual fiber
> optic star backbone, with two SUP2 CatOS boxes in the core. Because
> of the IGMP rate limit function, we saw random and intermittent
> multicast forwarding failures when the rate limiter would trigger.

     We don't have that many routers and apparently we aren't hit with
     the rate limiting issue. I tried increasing the limit but it had
     no effect. Every multicast flow that has gone via RP freezes when
     hardware swtiched. Strangely, the multicast between directly
     connected networks does work. 

> You can generate a trace of IGMP rate limiter activity with the CatOS
> commands:
> "set trace monitor enable"
> "set trace mcast 5"
>
> Be warned that this can generate a lot of output, and might overload
> a busy box.

     I was warned. Still, I had to learn this by hard way and try it.
     Well, some walking is always good for you :-)

     Cheers,
-- 
- Matti -