Re: Verifying SSM

On Wed, Mar 9, 2011 at 1:28 PM, Aaron <aaron1_at_gvtc.com> wrote:
> Please remind me if y'all know....i vaguely remember, something like
> this....
>
> Ip igmp join-group
>
> ip igmp static-group
>
> One of them DROVE THE CPU UP LIKE CRAZY HIGH, when I was testing with a
> couple hundred mbps of mcast traffic.....but the other one didn't. do you
> remember which causes CPU hit (perhaps its process switched based on
> something or the other)....sorry, I'm reaching for details that I don't
> recall, I just remember the Cisco tac telling me that there are different
> uses for each and don't recall the details...

ip igmp join-group causes the entire multicast stream to be punted to
the CPU because the router itself joins the group. ip igmp
static-group just creates an entry and sends a join upstream, but the
router CPU itself is not a recipient of the stream.

One downside is that if you use ip igmp static-group: since the router
itself is not joining the group, it will not respond to a ping if you
ping the group. So, if you're trying to create a join that will allow
you to test you connectivity, you pretty much have to use join-group
instead of static-group.

John

Blogs and organic groups at http://www.ccie.net
Received on Wed Mar 09 2011 - 14:27:26 ART