Configuration Guide User guide

1498 FastIron Configuration Guide
53-1002494-02
IGMP 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 through 8192 with a default of 512. However, for ICX 6430 devices, the range is from
256 through 1024, and the default is 256. Enter the system-max igmp-snoop-mcache command to
define the maximum number of IGMP snooping cache entries.
Brocade(config)# system-max igmp-snoop-mcache 8000
Syntax: [no] system-max igmp-snoop-mcache <num>
The system supports up to 32K of groups. The configurable range is from 256 through 32768 and
the default is 8192. However, for ICX 6430, the range is from 256 through 1024, and the default is
256, while for ICX 6450, the default is 4096. The configured number is the upper limit of an
expandable database. Client memberships exceeding the group limits are not processed. Enter the
system-max igmp-max-group-addr command to define the maximum number of IGMP group
addresses.
Brocade(config)# system-max igmp-max-group-addr 1600
Syntax: [no] system-max igmp-max-group-addr <num>
Enabling or disabling transmission and receipt of IGMP packets on a port
When a VLAN is snooping-enabled, all IGMP packets are trapped to CPU without hardware VLAN
flooding. The CPU can block IGMP packets to and from a multicast-disabled port, and does not add
it to the output interfaces of hardware resources. This prevents the disabled port from receiving
multicast traffic. However, if static groups to the entire VLAN are defined, the traffic from these
groups is VLAN flooded, including to disabled ports. Traffic from disabled ports cannot be blocked
in hardware, and is switched in the same way as traffic from enabled ports.
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)# ip-multicast-disable
Syntax: [no] ip-multicast-disable
Configuring the global IGMP mode
You can configure active or passive IGMP modes on an FWS, FCX, or ICX device. The default mode
is passive. If you specify an IGMP mode for a VLAN, it overrides the global setting.
• Active - When active IGMP mode is enabled, an FWS or FCX device actively sends out IGMP
queries to identify multicast groups on the network, and makes entries in the IGMP table
based on the group membership reports it receives.
• Passive - When passive IGMP mode is enabled, it forwards reports to the router ports which
receive queries. IGMP snooping in the passive mode does not send queries. However, it
forwards queries to the entire VLAN.
To globally set the IGMP mode to active, enter the ip multicast active command.
Brocade(config)# ip multicast active
Syntax: [no] ip multicast [active | passive]
If you do not enter either active or passive, the passive mode is assumed.