Configuration Guide User guide

1636 FastIron Configuration Guide
53-1002494-02
MLD snooping configuration
Configuring the hardware and software resource limits
The system supports up to 8K of hardware-switched multicast streams. The configurable range is
from 256 to 8192 and the default is 512.However, for ICX 6430, the range is from 256 to 1024,
and the default is 256, while for ICX 6450, the range is from 256 to 8192 with the default as 512.
Enter the system-max mld-snoop-mcache <num> command to define the maximum number of
MLD Snooping cache entries.
Brocade(config)#system-max mld-snoop-mcache 8000
Syntax: [no] system-max mld-snoop-mcache <num>
The system supports up to 32K of groups. The configurable range is 256 to 32768 and the default
is 8192. The configured number is the upper limit of an expandable database. Client memberships
exceeding the group limits are not processed.
Disabling transmission and receipt of MLD packets
on a port
When a VLAN is snooping-enabled, all MLD packets are trapped to the CPU without hardware VLAN
flooding. The CPU can block MLD packets to and from a multicast-disabled port, and will not add
that port to the output interfaces or hardware resources, which prevents the disabled port from
receiving multicast traffic. However, if static groups to the entire VLAN are defined, the traffic for
these groups is flooded to the entire VLAN, including to the disabled ports. Since the hardware
cannot block traffic from disabled ports, hardware traffic is switched in the same way as traffic
from enabled ports.
NOTE
This command has no effect on a VLAN that is not snooping-enabled because all multicast traffic is
VLAN flooded.
Brocade(config)#interface ethernet 0/1/3
Brocade(config-if-e1000-0/1/3)#ipv6-multicast-disable
Syntax: [no] ipv6-multicast-disable
Configuring the global MLD mode
You can configure a device for either active or passive (default) MLD mode. If you specify an MLD
mode for a VLAN, the MLD mode overrides the global setting:
• Active – In active MLD mode, the device actively sends out MLD queries to identify IPv6
multicast groups on the network, and makes entries in the MLD table based on the group
membership reports it receives from the network.
• Passive – In passive MLD mode, the device forwards reports to the router ports which receive
queries. MLD Snooping in passive mode does not send queries, but does forward queries to
the entire VLAN.
To globally set the MLD mode to active for the device, enter the ipv6 mld-snooping active
command.
Brocade(config)#ipv6 mld-snooping active
Syntax: [no] ipv6 mld-snooping [active | passive]