Owner's Manual

744 | Chapter 27. Multicast Routing and Switching

NETGEAR 8800 User Manual

enable pim

PIM Snooping Configuration Example

Figure 87 shows a network configuration that supports PIM snooping.

Figure 87. PIM Snooping Configuration Example

In Figure 87, Layer 3 switches S2, S3, S4, and S5 are connected using the Layer 2 switch

S1 through the VLAN comm_vlan. Switches S3, S4, and S5 are multicast capable switches,

and switch S2 is a non-multicast capable switch, which has no multicast routing protocol

running.

Without PIM snooping, any ingress multicast data traffic on comm_vlan is flooded to all the

switches, including switch S2, which does not support multicast traffic. IGMP snooping does

not reduce flooding because it floods the multicast traffic to all router ports.

The network design calls for most multicast traffic to egress switch S5. PIM snooping helps

by intercepting the PIM joins received from the downstream routers and forwarding multicast

traffic only to those ports that received PIM joins.

The following sections provide additional information for this example:

• Switch S1 (PIM Snooping Switch) Configuration Commands on page 745

• Switch S3 Configuration Commands on page 745

• Switch S5 Configuration Commands on page 745

• Switch S4 Configuration Commands on page 746

• Switch S2 Configuration Commands on page 746

• PIM Snooping Example Configuration Displays on page 747

(multicast switch)

receiver_vlan

(non-multicast switch)

(RP)

(LHR)

PIM_snooping_0002

sender_vlan

comm_vlan