PIM Snooping

PIM snooping provides a solution for handling multicast traffic on a shared media network more efficiently. In networks where routers are connected to a L2 switch, multicast traffic is essentially treated as broadcast traffic (see the following figure).

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Multicast Without PIM Snooping
../Graphics/EX_mcast_0018.svg

IGMP (Internet Group Management Protocol) snooping does not solve this flooding issue when routers are connected to a L2 switch. Switch ports are flooded with multicast packets. PIM snooping addresses this flooding behavior by efficiently replicating multicast traffic only onto ports which routers advertise the PIM join requests (see the following figure).

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Multicast With PIM Snooping
../Graphics/EX_mcast_0015.svg

PIM snooping does not require PIM to be enabled. However, IGMP snooping must be disabled on VLANs that use PIM snooping. PIM snooping and MVR cannot be enabled on the same VLAN.

To enable PIM snooping on one or all VLANs, use the following command:

enable pim snooping {{vlan} name}

To disable PIM snooping on one or all VLANs, use the following command:

disable pim snooping {{vlan} name}

Note

Note

PIM snooping can be enabled only between PIM SM enabled switches. It should not enabled between PIM DM enabled switches.