Technical data

BLADE OS 5.1 Application Guide
BMD00136, November 2009 Chapter 13: IGMP
 183
With FastLeave enabled on the VLAN, a port can be removed immediately from the port list of the
group entry when the IGMP Leave message is received, unless a multicast router was learned on the
port.
Enable FastLeave only on VLANs that have only one host connected to each physical port.
To enable FastLeave, use the following command:
IGMPv3 Snooping
IGMPv3 includes new membership report messages to extend IGMP functionality.
The switch provides snooping capability for all types of IGMP version 3 (IGMPv3)
Membership Reports.
IGMPv3 supports Source-Specific Multicast (SSM). SSM identifies session traffic by
both source and group addresses.
The IGMPv3 implementation keeps records on the multicast hosts present in the network.
If a host is already registered, when it sends an IS_INC/TO_INC/IS_EXC/TO_EXC report,
the switch overwrites the existing (port-host-group) registration with the new registration;
the registrations of other hosts on the same group, same port are not changed.
IS_INCLUDE/TO_INCLUDE reports with no source are not registered.
The switch supports the following IGMPv3 filter modes:
 INCLUDE mode: The host requests membership to a multicast group and provides a list of IP
addresses from which it wants to receive traffic.
 EXCLUDE mode: The host requests membership to a multicast group and provides
a list of IP addresses from which it does not want to receive traffic. This indicates that
the host wants to receive traffic only from sources that are not part of the Exclude list.
To disable snooping on EXCLUDE mode reports, use the following command:
By default, the switch snoops the first eight sources listed in the IGMPv3 Group Record.
Use the following command to change the number of snooping sources:
RS G8000 (config)# ip igmp fastleave <VLAN number (1-4094)>
RS G8000 (config)# no ip igmp snoop igmpv3 exclude
RS G8000 (config)# ip igmp snoop igmpv3 sources <1-64>