H3C Technologies H3C S12500 Series Switches - Manual (Page 62)

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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, will receive all
multicast data and all PIM messages except for PIM hello messages.
• When running both IGMP snooping and PIM snooping, the Layer 2 switch 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.
The term "router" in this document refers to both routers and Layer 3 switches.
For more information about IGMP snooping and the router port, see "Configuring IGMP snooping."
For more information about PIM, see "Configuring PIM."
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 take effect on the sub-VLANs of a multicast VLAN.
To configure PIM snooping:
Step 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.
For more information about multicast VLAN, see "Configuring multicast VLANs."
Displaying and maintaining PIM snooping
Task Command Remarks
Display PIM snooping neighbor
information (in standalone mode).
display pim-snooping neighbor
[ vlan vlan-id ] [ slot slot-number ]
[ | { begin | exclude | include }
regular-expression ]
Available in any view.