H3C Technologies H3C S3100 Series Switches - Manual (Page 310)

3-3
Ports involved in MLD snooping, as shown in Figure 3-2 , are described as follows:
z Router port: A router port is a port on the Ethernet switch that leads switch towards the Layer-3
multicast device (DR or MLD querier). In the figure, Ethernet 1/0/1 of Switch A and Ethernet 1/0/1 of
Switch B are router ports. The switch registers all its local router ports in its router port list.
z Member port: A member port (also known as IPv6 multicast group member port) is a port on the
Ethernet switch that leads towards multicast group members. In the figure, Ethernet 1/0/2 and
Ethernet 1/0/3 of Switch A and Ethernet 1/0/2 of Switch B are member ports. The switch registers
all the member ports on the local device in its MLD snooping forwarding table.
z Whenever mentioned in this document, a router port is a router-connecting port on the switch,
rather than a port on a router.
z Unless otherwise specified, router/member ports mentioned in this document include static and
dynamic ports.
z On an MLD snooping-enabled switch, the ports that received MLD general queries with the source
address other than 0::0 or IPv6 PIM hello messages are dynamic router ports.
Aging timers for dynamic ports in MLD Snooping
Table 3-1 Aging timers for dynamic ports in MLD snooping and related messages and actions
Timer Description Message before expiry Action after expiry
Dynamic router
port aging timer
For each dynamic router port,
the switch sets a timer initialized
to the dynamic router port aging
time. MLD general query of
which the source address
is not 0::0 or IPv6 PIM
hello.
The switch removes this
port from its router port
list.
Dynamic member
port aging timer
When a port dynamically joins
an IPv6 multicast group, the
switch sets a timer for the port,
which is initialized to the
dynamic member port aging
time.
MLD report message.
The switch removes this
port from the MLD
snooping forwarding
table.
The port aging mechanism of MLD snooping works only for dynamic ports; a static port will never age
out.
How MLD Snooping Works
A switch running MLD snooping performs different actions when it receives different MLD messages, as
follows: