Operation Manual

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The solicited-node multicast address is a multicast group that corresponds to an IPv6 unicast
or anycast address. It is usually used for obtaining the Layer 2 link-layer addresses of
neighboring nodes within the local-link or applied in IPv6 Duplicate Address Detection. A node
is required to join the associated Solicited-Node multicast addresses for all unicast and
anycast addresses that have been configured for the node's interfaces.
IPv6 Solicited-Node Multicast Address Format:
FF02:0:0:0:0:1:FFXX:XXXX
The IPv6 solicited-node multicast address has the prefix FF02:0:0:0:0:1:FF00:0000/104
concatenated with the 24 low-order bits of a corresponding IPv6 unicast or anycast address.
2. IPv6 Multicast MAC Address
The high-order 16 bits of an IPv6 multicast MAC address begins with 0x3333 while the
low-order 32 bits of an IPv6 multicast MAC address are the low-order 32 bits of the IPv6
multicast IP address. The mapping relationship is described as the following figure:
Figure 10-3 Mapping relationship between multicast IPv6 address and multicast IPv6 MAC
address
The high-order 16 bits of the IP multicast address are 0x3333, identifying the IPv6 multicast
group. The low-order 32 bits of the IPv6 multicast IP address are mapped to the multicast MAC
address.
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Multicast Address Table
The switch is forwarding multicast packets based on the multicast address table. As the
transmission of multicast packets cannot span the VLAN, the first part of the multicast address
table is VLAN ID, based on which the received multicast packets are forwarded in the VLAN
owning the receiving port. The multicast address table is not mapped to an egress port but a
group port list. When forwarding a multicast packet, the switch looks up the multicast address
table based on the destination multicast address of the multicast packet. If the corresponding
entry cannot be found in the table, the switch will broadcast the packet in the VLAN owning the
receiving port. If the corresponding entry can be found in the table, it indicates that the
destination address should be a group port list, so the switch will duplicate this multicast data
and deliver each port one copy. The general format of the multicast address table is described
as Figure 10-4 below.
VLAN ID
Multicast IP
Port