All things related to multicast

[Bruce Curtis <>]

On Sep 26, 2007, at 1:45 PM, <>  
<> wrote:

> Hello !
>
>             We use a lot of multicast on the LAN. The throughputs  
> of multicast traffics seem to vary a lot during the day and ghost  
> operation are not reliable on the LAN.  We use Catalyst 6500 with  
> Sup720  PIM- Sparce-dense mode. During the day, Cpu, memory and  
> link utilization doesn’t seem to be busy enough to affect  
> performance.  At night Ghost are very fast so the problem point to  
> my switch.  Maybe I am not monitoring the right variable on my  
> Catalyst 6500 to link this performance issue with a certain  
> chokepoint in my Catalyst.
>
>
>
>             Many CCIE came to solve our multicast/Ghost problem but  
> nobody ever succeeded. If anybody can suggest item I might have  
> overlook or I should investigate let me know off line. We have  
> validated the configuration with auto-RP and pim-sparce-dense mode.
>
>
>
> Thanks,
>
>
>
> Christian Héroux

  Do you have other switches between your 6500 and the server and/or  
the clients?

  Do you have IGMP snooping enabled on the 6500 and the other  
switches (if there are any others in the path)?

  If IGMP v2 is being used one of the switches might be having  
problems snooping all of the Ghost traffic plus it's normal load  
during the day, but might be keeping up during the night when the  
load from normal traffic is lower.

  If your switches support IGMP v3 snooping and the Ghost server and  
clients do also that would lower the load on the switch since it  
wouldn't have to look at every Ghost packet to see if it's an IGMP  
packet.

---
Bruce Curtis                         

Certified NetAnalyst II                701-231-8527
North Dakota State University