H3C S5500-EI - Configuring PIM Snooping

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• When the Layer 2 switch runs only IGMP snooping, it maintains the router ports according to the
received PIM hello messages that PIM-capable routers send, broadcasts all other types of received
PIM messages in the VLAN, and forwards all multicast data to all router ports in the VLAN. Each
PIM-capable router in the VLAN, whether interested in the multicast data or not, can receive all
multicast data and all PIM messages except PIM hello messages.
• When the Layer 2 switch runs both IGMP snooping and PIM snooping, it determines whether
PIM-capable routers are interested in the multicast data addressed to a multicast group according
to PIM messages received from the routers, and adds only the ports for connecting the routers that
are interested in the data to a multicast forwarding entry. Then, the Layer 2 switch forwards PIM
messages and multicast data to only the routers that are interested in the data, saving network
bandwidth.
For more information about IGMP snooping and the router port, see "Configuring IGMP snooping."
F
or more information about PIM, see "Configuring PIM (available only on the S5500-EI)."
Configuring PIM snooping
When you configure PIM snooping, follow these guidelines:
• Before configuring PIM snooping for a VLAN, be sure to enable IGMP snooping globally and
specifically for the VLAN.
• After you enable PIM snooping in a VLAN, PIM snooping works only on the member interfaces of
the VLAN.
• PIM snooping does not work in the sub-VLANs of a multicast VLAN. For more information about
multicast VLAN, see "Configuring multicast VLANs."
• In a network with PIM snooping enabled switches, configure the size of each join/prune message
no more than the path maximum transmission unit (MTU) on the PIM-enabled edge router on the
receiver side. For more information about the join/prune messages, see "Configuring PIM
(
available only on the S5500-EI)."
To configure PIM snooping:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enable IGMP snooping
globally and enter
IGMP-snooping view.
igmp-snooping Disabled by default
3. Return to system view.
quit N/A
4. Enter VLAN view.
vlan vlan-id N/A
5. Enable IGMP snooping in the
VLAN.
igmp-snooping enable
Disabled by default
6. Enable PIM snooping in the
VLAN.
pim-snooping enable Disabled by default