Work Mechanism Of Mld Snooping - H3C S3610 Series Operation Manual

Operation Manual – Multicast Protocol
H3C S3610&S5510 Series Ethernet Switches
II. Port aging timers in MLD Snooping
Table 3-1 Port aging timers in MLD Snooping and related messages and actions
Timer
Router port aging
timer
Member port aging
timer

3.1.3 Work Mechanism of MLD Snooping

A switch running MLD Snooping performs different actions when it receives different
MLD messages, as follows:
I. General queries
The MLD querier periodically sends MLD general queries to all hosts and routers on the
local subnet to find out whether IPv6 multicast group members exist on the subnet.
Upon receiving an MLD general query, the switch forwards it through all ports in the
VLAN except the receiving port and performs the following to the receiving port:
If the receiving port is a router port existing in its router port list, the switch resets
the aging timer of this router port.
If the receiving port is not a router port existing in its router port list, the switch adds
it into its router port list and sets an aging timer for this router port.
II. Membership reports
A host sends an MLD report to the multicast router in the following circumstances:
Upon receiving an MLD query, an IPv6 multicast group member host responds
with an MLD report.
When intended to join an IPv6 multicast group, a host sends an MLD report to the
multicast router to announce that it is interested in the multicast information
addressed to that IPv6 multicast group.
Description
For each router
MLD
port, the switch
query or IPv6 PIM
sets a timer
hello message of
initialized to the
which the source
aging time of the
address is not 0::0
route port
When a port joins
an IPv6 multicast
group, the switch
sets a timer for the MLD
port, which is message
initialized to the
member port aging
time
3-3
Chapter 3 MLD Snooping Configuration
Message before
expiry
general
The
removes this port
from its router port
list
The
removes this port
report
from
multicast
forwarding table
Action after
expiry
switch
switch
the IPv6
group