Configuring Pim Snooping - HP A8800 Configuration Manual

Configuring PIM snooping

Overview
Protocol Independent Multicast (PIM) snooping runs on Layer 2 devices. It determines which ports are
interested in multicast data by analyzing the received PIM messages, and adds the ports to a multicast
forwarding entry to make sure that multicast data can be forwarded to only the ports that are interested
in the data.
Figure 18 Multicast packet transmission without or with PIM snooping
Multicast packet transmission
when only IGMP snooping runs
Source 1
PIM
router 1
PIM
router 3
Receiver 1
As shown in
multicast data to multicast group G2. Receiver 1 belongs to G1, and Receiver 2 belongs to G2. The Layer
2 switch's interfaces that connect to the PIM-capable routers are in the same VLAN.
Source 2
Layer 2 switch
Receiver 2
Multicast packets (S1, G1)
Multicast packets (S2, G2)
Figure 18, Source 1 sends multicast data to multicast group G1, and Source 2 sends
PIM PIM
router 2 router 1
PIM PIM
router 4 router 3
Receiver 1
48
Multicast packet transmission when
IGMP snooping and PIM snooping both run
Source 1
Join message (S1, G1)
Join message (S2, G2)
Source 2
PIM
router 2
Layer 2 switch
PIM
router 4
Receiver 2