This article shows how to verify if the Multicast stream for a specific Multicast group has been received on the Last-Hop Router (LHR).

When troubleshooting a Multicast issue in KB21586 - Resolution Guide - Troubleshoot Multicast issue with Junos OS device configured as Layer 3 (running PIM protocol) [juniper.net] you may need to check if the LHR has received the Multicast stream (traffic) from the source address S, for the Multicast Group G.

The following network topology is referenced in the solution:

Note : Refer to KB21591 - Sample Multicast Network Topology with Junos OS devices [juniper.net] for locating the LHR and definitions of the components.

On the LHR, run the following commands to verify if the LHR has received the Multicast stream from the source address S, for the Multicast group G:

root@LHR> show multicast route group <group address>
root@LHR> show multicast route extensive group <group address>

Below is an example of the expected output for the network topology above:

{master:0}[edit]
root@LHR# run show multicast route group 224.100.100.100
Family: INET

Group: 224.100.100.100  <----
    Source: 192.168.200.10/32   <----
    Upstream interface: ge-0/0/20.0
    Downstream interface list:
        vlan.100

root@LHR# run show multicast route extensive group 224.100.100.100
Family: INET

Group: 224.100.100.100   <----
    Source: 192.168.200.10/32   <----
    Upstream interface: ge-0/0/20.0
    Downstream interface list:
        vlan.100
    Session description: Unknown
    Statistics: 0 kBps, 0 pps, 332 packets
    Next-hop ID: 131071
    Upstream protocol: PIM
    Route state: Active
    Forwarding state: Forwarding
    Cache lifetime/timeout: 358 seconds
    Wrong incoming interface notifications: 0

In this example, the Multicast Group 224.100.100.100 is seen with the source 192.168.200.10 streaming for that group.

If the concerned Multicast Group is not listed or if the source of the traffic is not the intended source, refer to KB21586 - Resolution Guide - Troubleshoot Multicast issue with Junos OS device configured as Layer 3 (running PIM protocol) [juniper.net] for further troubleshooting.

For an explanation of the fields in the show multicast route and show multicast route extensive commands, refer to show multicast route .

2020-05-07: Article reviewed for accuracy; no changes required; article valid and accurate