Brocade BigIron RX Series Configuration Guide - Manual (Page 1231)

BigIron RX Series Configuration Guide 1153
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Enabling IP multicast traffic reduction
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NOTE
If the route-only feature is enabled on the device, then IP Multicast Traffic Reduction will not be
supported.
Also, this feature is not supported on the default VLAN of the BigIron RX.
To verify that IP Multicast Traffic Reduction is enabled, enter the following command at any level of
the CLI.
BigIron RX(config)# show ip multicast
IP multicast is enabled - Active
Syntax: show ip multicast
Changing the IGMP mode
When you enable IP Multicast Traffic Reduction on the device, IGMP also is enabled. The device
uses IGMP to maintain a table of the Group Membership reports received by the device. You can
use active or passive IGMP mode. There is no default mode.The IGMP modes are as follows:
• Active – When active IGMP mode is enabled, a Brocade device actively sends out IGMP queries
to identify IP multicast groups on the network and makes entries in the IGMP table based on
the Group Membership reports received from the network.
NOTE
Routers in the network generally handle this operation. Use the active IGMP mode only when
the device is in a stand-alone Layer 2 Switched network with no external IP multicast router
attachments. In this case, enable the active IGMP mode on only one of the devices and leave
the other devices configured for passive IGMP mode.
• Passive – When passive IGMP mode is enabled, the device listens for IGMP Group
Membership reports but does not send IGMP queries. The passive mode is sometimes called
“IGMP snooping”. Use this mode when another device in the network is actively sending
queries.
To enable active IGMP, enter the following command.
BigIron RX(config)# ip multicast active
BigIron RX(config)# write memory
BigIron RX(config)# end
BigIron RX# reload
Syntax: [no] ip multicast active | passive
To enable passive IGMP, enter the following command.
BigIron RX(config)# ip multicast passive
BigIron RX(config)# write memory
BigIron RX(config)# end
BigIron RX# reload
Configuring the IGMP mode per VLAN instance
If the IP Multicast command is not applied globally as described in “Enabling IP multicast traffic
reduction” on page 1152, you can apply it to individual VLANs instances within their configurations.
In the following example, multicast traffic reduction is applied using IGMP snooping to VLAN 2.