3Com Switch 8800 Advanced Software V5 Configuration Guide

528 CHAPTER 40: IGMP CONFIGURATION
■ If a feature is not configured for an interface in interface view, the global
configuration performed in IGMP view will apply to that interface. If a feature
is configured in both IGMP view and interface view, the configuration
performed in interface view will be given priority.
Configuring Basic
Functions of IGMP
Configuration
Prerequisites
Before configuring the basic functions of IGMP, complete the following tasks:
■ Configure any unicast routing protocol so that all devices in the domain are
interoperable at the network layer.
■ Configure PIM-DM or PIM-SM
Before configuring the basic functions of IGMP, prepare the following data:
■ IGMP version
■ Multicast group and multicast source addresses for static group member
configuration
■ ACL rule for multicast group filtering
Enabling IGMP First, IGMP must be enabled on the interface on which the multicast group
memberships are to be established and maintained.
Follow these steps to enable IGMP:
c
CAUTION:
■ Hosts can join multicast groups only if IGMP is enabled on the receiver-side DR.
For more information about a DR, refer to
“PIM Configuration” on page 563.
■ After IGMP is enabled on a VLAN interface, IGMP snooping cannot be enabled
in the VLAN corresponding to the VLAN interface, and vice versa.
Configuring IGMP
Versions
Because messages vary with different IGMP versions, the same IGMP version
should be configured for all devices on the same subnet before IGMP can work
properly.
Configuring an IGMP version globally
Follow these steps to configure an IGMP version globally:
To do... Use the command... Description
Enter system view system-view -
Enable IP multicast routing multicast routing-enable Required
Disabled by default
Enter VLAN/POS interface
view
interface interface-type
interface-number
-
Enable IGMP igmp enable Required
Disabled by default