R21xx-HP FlexFabric 11900 IP Multicast Configuration Guide

107
Timer Description
Message received
before the timer
ex
p
ires
Action after the timer
expires
Dynamic
member port
aging timer.
When a port dynamically joins a
multicast group, the switch starts an
aging timer for the port. When the
timer expires, the dynamic member
port ages out.
MLD report message.
The switch removes the
port from the MLD
snooping forwarding
table.
NOTE:
In MLD snooping, only dynamic ports age out. Static ports never age out.
How MLD snooping works
The ports in this section are dynamic ports. For information about how to configure and remove static
ports, see "Configuring static ports."
A
n MLD snooping-enabled switch performs different actions upon receiving the following different MLD
messages:
General query
The MLD querier periodically sends MLD general queries to all hosts and routers identified by the address
FF02::1 on the local subnet to determine whether any active IPv6 multicast group members exist on the
subnet.
After receiving an MLD general query, the switch forwards the query to all ports in the VLAN except the
port that received the query. The switch also performs one of the following actions:
• If the receiving port is a dynamic router port in the router port list, the switch restarts the aging timer
for the router port.
• If the receiving port does not exist in the router port list, the switch adds the port to the router port
list, and starts an aging timer for the port.
MLD report
A host sends an MLD report to the MLD querier for the following purposes:
• Responds to queries if the host is an IPv6 multicast group member.
• Applies for an IPv6 multicast group membership.
After receiving an MLD report, the switch forwards it through all the router ports in the VLAN, resolves the
IPv6 address of the reported IPv6 multicast group, and performs one of the following actions:
• If no forwarding entry matches the group address, the switch creates a forwarding entry for the
group, adds the receiving port as a dynamic member port to the forwarding entry for the group,
and starts an aging timer for the port.