Igmpv3 snooping – Juniper Networks EX2500 User Manual

Page 89

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IGMPv3 Snooping

„

75

Chapter 7: IGMP

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:

ex2500(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

, or

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

and

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:

ex2500(config)

#

no ip igmp snoop igmpv3 exclude

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:

ex2500(config)

#

ip igmp snoop igmpv3 sources

<1-64>

IGMPv3 Snooping is compatible with IGMPv1 and IGMPv2 Snooping. You can
disable snooping on version 1 and version 2 reports, with the following command:

ex2500(config)

#

no ip igmp snoop igmpv3 v1v2

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