51
•
Facilitating the implementation of per-host accounting.
Basic concepts in MLD snooping
MLD snooping related ports
As shown in
, Router A connects to the multicast source, MLD snooping runs on Switch A
and Switch B, Host A and Host C are receiver hosts—namely, IPv6 multicast group members.
Figure 21 MLD snooping related ports
Ports involved in MLD snooping, as shown in
, are described as follows:
•
Router port—A router port is a port on the Ethernet switch that leads the switch toward the
Layer-3 multicast device—DR or MLD querier. In the figure, GigabitEthernet 1/0/1 of Switch A
and GigabitEthernet 1/0/1 of Switch B are router ports. The switch registers all its local router
ports in its router port list.
•
Member port—A member port—also known as "IPv6 multicast group member port"—is a port
on the Ethernet switch that leads toward multicast group members. In the figure,
GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 of Switch A and GigabitEthernet 1/0/2 of
Switch B are member ports. The switch registers all the member ports on the local switch in its
MLD snooping forwarding table.
NOTE:
•
In this document, a router port is a router-connecting port on the switch, rather than a port on a
router.
•
Unless otherwise specified, router ports and member ports in this document include static and
dynamic ports.
•
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 8 Aging timers for dynamic ports in MLD snooping and related messages and actions
Timer Description
Message before
expiry
Action after expiry
Dynamic router port
For each dynamic router
MLD general query of
The switch removes this
Router A
Switch A
Switch B
GE1/0/1
GE1/0/2
GE1/0/3
GE1/0/1
GE1/0/2
Receiver
Receiver
Host A
Host B
Host C
Host D
Source
IPv6 multicast packets
Router port
Member port