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IPv6 multicast forwarding across IPv6 unicast subnets
Routers forward the IPv6 multicast data from an IPv6 multicast source hop by hop along the
forwarding tree, but some routers might not support IPv6 multicast protocols in a network. When the
IPv6 multicast data is forwarded to a router that does not support IPv6 multicast, the forwarding path
is blocked. In this case, you can enable IPv6 multicast data forwarding across the IPv6 unicast
subnets by establishing a tunnel between the routers at both ends of the IPv6 unicast subnets.
Figure 103 IPv6 multicast data transmission through a tunnel
As shown in
, a tunnel is established between the multicast routers Device A and Device
B. Device A encapsulates the IPv6 multicast data in unicast IPv6 packets, and forwards them to
Device B across the tunnel through unicast routers. Then, Device B strips off the unicast IPv6 header
and continues to forward the IPv6 multicast data down toward the receivers.
Configuration task list
Tasks at a glance
Enabling IPv6 multicast routing
(Optional.)
Configuring IPv6 multicast routing and forwarding
•
(Optional.)
Specifying the longest prefix match principle
•
(Optional.)
Configuring IPv6 multicast load splitting
•
(Optional.)
Configuring an IPv6 multicast forwarding boundary
•
Enabling IPv6 multicast forwarding between sub-VLANs of a super VLAN
Enabling IPv6 multicast routing
Enable IPv6 multicast routing before you configure any Layer 3 IPv6 multicast functionality in the
public network or VPN instance.
To enable IPv6 multicast routing:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enable IPv6 multicast
routing and enter IPv6
MRIB view.
ipv6 multicast routing
[
vpn-instance
vpn-instance-name
]
By default, IPv6 multicast routing
is disabled.
Tunnel
IPv6 unicast device
IPv6 multicast deivce
Device A
Source
Receiver
Device B
IPv6 multicast device
IPv6 unicast device
IPv6 unicast device
IPv6 unicast device