What's the difference between IGMP snooping and PIM snooping?

FrankGuthrie

What's the difference between IGMP snooping and PIM snooping?

Dieg0M

IGMP snooping only acts on the L2 segment up to the first hop router elected as DR. The process is like this:
1. The IGMP membership report is flooded to all routers on the segment.
2. The elected DR of this L2 segment will then forward a PIM Join message towards the RP.
3. In the case where there is a multiaccess network after the router, the PIM Join will be flooded in that L2 segment

When PIM snooping is active, join/prune messages are not flooded through the multiaccess network and are only sent to the port corresponding to the upstream router mentioned in the payload of the join or prune message.

FrankGuthrie

So can you say that IGMP is used for Host/Client/PC Multicast registrations, and that PIM is used for Router Multicast registration?? Or is this too simple?

Dieg0M

That is correct. Glad it is clear for you now.

FrankGuthrie

I thought I was looking at it too simple, thanks for the help