Foundry Networks AR1216, AR3202-CL, AR3201-CL, AR1204 manual Internet Group Management Protocol Igmp

Foundry AR-Series Router User Guide

TABLE 5 PIM SHOW AND DEBUG COMMANDS (CONTINUED)

Display PIM Candidate	Foundry#show ip pim crp-info
RP info
Display PIM statistics	Foundry#show ip pim statistics
Display PIM RP set	Foundry#show ip pim rp-set
Display PIM Static RP	Foundry#show ip pim rp
Trace PIM packets	Foundry# debug ip pim packet <pkt_type# <direction#
	[interface_name ] [ dlci ]
Trace PIM state	Foundry# debug ip pim state
changes
Trace PIM routes	Foundry# debug ip pim route
Trace PIM detail	Foundry# debug ip pim detail
Trace PIM debug	Foundry# debug ip pim debug
All Traces	Foundry#debug ip pim all

Protocol Independent Multicast - Source Specific Multicast (PIM-SSM)

By running PIM-SSM and IGMPv3, you can implement a Source Specific Multicast (SSM) service model in your network. PIM-SSM functionality is the subset of PIM-SM functionality dealing only with source-specific distribution trees. IGMPv3 provides a way to detect channel subscriptions; for example, host-initiated (S,G) joins where G falls within the defined range of SSM multicast group addresses.

PIM-SSM can be run in the absence of IGMPv3. Even when they are both running, they do not need to run on the same interfaces. For example, you might not want to run PIM-SSM (or PIM-SM, for that matter) over an interface that leads to a stub network. Similarly, if a network cannot contain local IGMPv3 receivers (for example, on a DMZ network), then there is no need to run IGMPv3.

The PIM-SSM command is ip pim ssm-range.

Internet Group Management Protocol (IGMP)

Internet Group Management Protocol (IGMP) is enabled on hosts and routers that want to receive multicast traffic. IGMP informs locally-attached routers of their multicast group memberships. Hosts inform routers of the groups of which they are members by multicasting IGMP Group Membership Reports. When multicast routers listen for these reports, they can exchange group membership information with other multicast routers. This reporting system allows distribution trees to be formed to deliver multicast datagrams. The original version of IGMP was defined in RFC 1112, Host Extensions for IP Multicasting. Extensions to IGMP, known as IGMP version 2.

IGMPv2 improves performance and supports the following message types:

•IGMP Query: IGMP Query is sent by the router to know which groups have members on the attached network.

•IGMP Reports: IGMP reports are sent as a response to the query by hosts to announce their group membership. Reports can be sent “unsolicited” when the hosts come up.

•IGMP Leaves: IGMP Leaves are sent by the host when it relinquishes membership of a group.

The latest extension to the IGMP standard is Version 3, which includes interoperability with version 2 and version 1 hosts, also provides support for source filtering. Source filtering enables a multicast receiver host to signal to a router which groups it wants to receive multicast traffic from, and from which source(s) this traffic is expected. This

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