Blade ICE G8000 manual FastLeave, IGMPv3 Snooping

RackSwitch G8000 Application Guide

FastLeave

In normal IGMP operation, when the switch receives an IGMPv2 Leave message, it sends a Group-Specific Query to determine if any other devices in the same group (and on the same port) are still interested in the specified multicast group traffic. The switch removes the affili- ated port from that particular group, if the following conditions apply:

„If the switch does not receive an IGMP Membership Report within the query-response- interval.

„If no multicast routers have been learned on that port.

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:

RS G8000 (config)# ip igmp fastleave <VLAN number (1-4094)>

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.

BMD00041, November 2008 Chapter 9: IGMP „ 131