How Mld Snooping Works - 3Com 4510G Configuration Manual

Whenever mentioned 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/member ports mentioned 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 4-1 Aging timers for dynamic ports in MLD Snooping and related messages and actions
Timer
Dynamic router
port aging timer
Dynamic
member port
aging timer
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:
The description about adding or deleting a port in this section is only for a dynamic port. Static ports
can be added or deleted only through the corresponding configurations. For details, see
Static Ports.
Description
For each dynamic router
port, the switch sets a timer
initialized to the dynamic
router port aging time.
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.
Message before
expiry
MLD general query of
which the source
address is not 0::0 or
IPv6 PIM hello.
MLD report message.
4-3
Action after expiry
The switch removes
this port from its router
port list.
The switch removes
this port from the MLD
Snooping forwarding
table.
Configuring