All things related to multicast

["Richard Mavrogeanes" <>]

One problem I remember about CGMP is ports flood if there is not at
least one group member. Plus it uses router CPU which can be a problem
in heavy loads.

/rich
 

-----Original Message-----
From: David Farmer 
[mailto:]
 
Sent: Thursday, February 16, 2006 6:13 PM
To: Roy D. Hockett
Cc: 

Subject: Re: catalyst 1900 and Multicast

Basically, we were able to make it work, but that was a while ago.  Your
router needs to do CGMP, which means it must be a Cisco, at least I
haven't heard of any other routers that do CGMP.  If you have a mixture
of switches, some doing CGMP and others doing IGMP snooping, you have to
be very careful. Cisco has a white paper or config note on how to make
that situation work. 

Personally, I liked the idea of CGMP, it had the router making Layer 3
decisions and telling the switchs which end stations wanted which
groups.  
But, I really don't think Cisco has continued development of it, so I'm
not sure how well it will works with things like IGMPv3 and SSM.  And,
while I liked the design it still had some problems, which I can't
completely remember. 

On 16 Feb 2006 Roy D. Hockett wrote:  

> 
> Anyone have any experience with running CGMP/multicast on the catalyst

> 1900 switches?  If so what are you what isssues have you run into?
> 
> Thanks,
> --Roy
> 
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