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Example: Configuring PIM SSM on a Network

The following example shows how PIM SSM is configured between a receiver and a source in the network illustrated in Figure 1.

Figure 1: Network on Which to Configure PIM SSMNetwork on Which to Configure PIM SSM

This example shows how to configure the IGMP version to IGMPv3 on all receiving host interfaces.

  1. Enable IGMPv3 on all host-facing interfaces, and disable IGMP on the fxp0.0 interface on Router 1.


    When you configure IGMPv3 on a router, hosts on interfaces configured with IGMPv2 cannot join the source tree.

  2. After the configuration is committed, use the show configuration protocol igmp command to verify the IGMP protocol configuration.

  3. Use the show igmp interface command to verify that IGMP interfaces are configured.

  4. Use the show pim join extensive command to verify the PIM join state on Router 2 and Router 3 (the upstream routers).

  5. Use the show pim join extensive command to verify the PIM join state on Router 1 (the router connected to the receiver).


IP version 6 (IPv6) multicast routers use the Multicast Listener Discovery (MLD) Protocol to manage the membership of hosts and routers in multicast groups and to learn which groups have interested listeners for each attached physical networks. Each routing device maintains a list of host multicast addresses that have listeners for each subnetwork, as well as a timer for each address. However, the routing device does not need to know the address of each listener—just the address of each host. The routing device provides addresses to the multicast routing protocol it uses, which ensures that multicast packets are delivered to all subnetworks where there are interested listeners. In this way, MLD is used as the transport for the Protocol Independent Multicast (PIM) Protocol. MLD is an integral part of IPv6 and must be enabled on all IPv6 routing devices and hosts that need to receive IP multicast traffic. The Junos OS supports MLD versions 1 and 2. Version 2 is supported for source-specific multicast (SSM) include and exclude modes.