Allied Telesis 86253-07 - Manual (Page 30)

30 SHOW IGMPSNOOPING ROUTERADDRESS Patch Release Note
Patch 86253-07 for Software Release 2.5.3
C613-10382-00 REV E
MLD Snooping
Multicast Listener Discovery (MLD) snooping enables the switch to forward
IPv6 multicast traffic intelligently, instead of flooding it out all ports in the
VLAN. With MLD snooping, the switch passively listens to MLD joins/reports
and leaves/done messages, to identify the switch ports that have received joins
and/or leaves from devices attached to them. Multicast traffic will only be
forwarded to those ports. MLD snooping will also identify ports that are
connected to another router or switch and forward messages out those ports
appropriately.
MLD snooping is performed at Layer 2 on VLAN interfaces automatically. By
default, the switch will only forward traffic out those ports with routers or IPv6
multicast listeners, therefore it will not act as a simple hub and flood all IPv6
multicast traffic out all ports. MLD snooping is independent of the MLD and
Layer 3 configuration, so an IPv6 interface does not have to be attached to the
VLAN, and MLD does not have to be enabled or configured.
MLD snooping is enabled by default. To disable it, use the command:
DISABLE MLDSNOOPING
Note that IPv6 multicast packets will flood the VLAN when MLD snooping is
disabled.
To enable MLD snooping, use the command:
ENABLE MLDSNOOPING
To display debugging information, use the command:
ENABLE MLDSNOOPING DEBUG
This command displays the ports that are currently receiving MLD packets and
the ports that are being added or taken off the switch’s multicast group
membership registration.
To disable debugging, use the command:
DISABLE MLDSNOOPING DEBUG
To display information about MLD snooping, use the command:
SHOW MLDSNOOPING COUNTER
For more information, including limitations on which addresses and packet
types can be snooped, see the IPv6 Multicasting chapter of the Software
Reference.
Table 6: Parameters in the output of the SHOW IP ICMPREPLY command.
Parameter Meaning
ICMP Reply Messages A list of ICMP configurable reply messages and whether
they are enabled or disabled.