309• When running MLD snooping without IPv6 PIM snooping, the Layer 2 switch maintains the routerports according to IPv6 PIM hello messages received from IPv6 PIM-capable routers, broadcasts allother types of received IPv6 PIM messages in the VLAN, and forwards all multicast data to all routerports in the VLAN. Each IPv6 PIM-capable router in the VLAN, whether interested in the multicastdata or not, will receive all multicast data and all IPv6 PIM messages except for IPv6 PIM hellomessages.• If the Layer 2 switch runs both MLD snooping and IPv6 PIM snooping, it determines whether an IPv6PIM-capable router is interested in the multicast data destined for a multicast group according to thereceived IPv6 PIM messages that the router sends, and adds the port that connects to the router toa multicast forwarding entry. Then, the Layer 2 switch can correctly forward IPv6 PIM messages andthe multicast data only to the router according to the multicast forwarding entry, saving networkbandwidth.For more information about MLD snooping and the router port, see "Configuring MLD snooping."For more information about IPv6 PIM, see "Configuring IPv6 PIM (available only on the S5500-EI)."Configuring IPv6 PIM snoopingWhen you configure IPv6 PIM snooping, follow these guidelines:• Before you configure IPv6 PIM snooping for a VLAN, you must enable IPv6 forwarding and MLDsnooping globally and enable MLD snooping in the VLAN.• IPv6 PIM snooping does not work in the sub-VLANs of a multicast VLAN. For more informationabout IPv6 multicast VLAN, see "Configuring IPv6 multicast VLANs."• In a network with IPv6 PIM snooping enabled switches, configure the size of each join/prunemessage no more than the path maximum transmission unit (MTU) on the IPv6 PIM-enabled edgerouter on the receiver side. For more information about the join/prune messages, see "ConfiguringIPv6 PIM (available only on the S5500-EI)."• After you enable IPv6 PIM snooping in a VLAN, IPv6 PIM snooping works only on the memberinterfaces of the VLAN.To configure IPv6 PIM snooping:Step Command Remarks1. Enter system view. system-view N/A2. Enable IPv6 forwardingglobally. ipv6 Disabled by default3. Enable MLD snoopingglobally and enterMLD-snooping view.mld-snooping Disabled by default4. Return to system view. quit N/A5. Enter VLAN view. vlan vlan-id N/A6. Enable MLD snooping in theVLAN. mld-snooping enable Disabled by default