H3C Technologies H3C S12500 Series Switches - Manual (Page 349)

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packet arrived is the RPF interface, the router forwards the packet out of all the outgoing
interfaces. Otherwise it discards the packet.
NOTE:
The switch allows you to configure special processing of IPv6 multicast packets that have failed an RPF
check instead of simply dropping them. For more information, see "
Configuring RPF check failure
processing ."
As shown in Figure 90 , assume that IPv6 unicast routes are available in the network, IPv6 MBGP is not
configured, and IPv6 multicast packets travel along the SPT from the multicast source to the receivers. The
IPv6 multicast forwarding table on Device C contains the (S, G) entry, with VLAN-interface 100 as the
RPF interface.
Figure 90 RPF check process
• When an IPv6 multicast packet arrives on VLAN-interface 100 of Device C, because the interface
is the incoming interface of the (S, G) entry, the router forwards the packet out of all outgoing
interfaces.
• When an IPv6 multicast packet arrives on VLAN-interface 101 of Device C, because the interface
is not the incoming interface of the (S, G) entry, the router performs an RPF check on the packet. The
router searches its IPv6 unicast routing table and finds that the outgoing interface to Source (the RPF
interface) is VLAN-interface 100. This means that the (S, G) entry is correct and the packet arrived
along a wrong path. The RPF check fails and the packet is discarded.
Configuration task list
Task Remarks
Enabling IPv6 multicast routing Required.
Configuring IPv6 multicast
routing and forwarding
Configuring an IPv6 multicast routing policy Optional.
Configuring an IPv6 multicast forwarding range Optional.
Configuring the IPv6 multicast forwarding table size Optional.
Configuring IPv6 static multicast MAC address entries Optional.
Receiver
Receiver
Source
2000::101/16 Device A
Device B
Device C
Vlan-int101
IPv6 Multicast packets
Destination/Prefix
IPv6 Routing Table on Device C
2000::/16
Interface
Vlan-int100
Vlan-int101
Vlan-int100