Description

This article shows how to verify whether the Rendezvous Point (RP) information is configured on the Last-Hop Router (LHR).

Symptoms

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 Rendezvous Point (RP) is configured for the Multicast group on the Last-Hop Router (LHR).

On the LHR, do you see the RP and the Multicast Group configured?

The following network topology is referenced in the solution:

  multicast topology diagram of 4 devices.

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

Solution

Run the following commands to view information about the RP.

root@LHR> show pim rps
root@LHR> show pim rps extensive 

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

root@LHR> show pim rps    
Instance: PIM.master

address-family INET
RP address      Type        Mode   Holdtime Timeout Groups Group prefixes
10.10.10.1      static      sparse        0    None      1 224.0.0.0/4

address-family INET6

root@LHR> show pim rps extensive 
Instance: PIM.master

address-family INET

RP: 10.10.10.1
Learned via: static configuration
Mode: Sparse
Time Active: 01:27:04
Holdtime: 0
Device Index: 25
Subunit: 32769
Interface: pime.32769
Static RP Override: Off
Group Ranges:
        224.0.0.0/4
Register State for RP:
Group           Source          FirstHop        RP Address      State    Timeout
239.255.0.1     192.168.200.2   10.10.10.4      10.10.10.1      Suppress      20

For an explanation of the fields in these commands " show pim rps " and " show pim rps extensive ," refer to show pim rps .

In this example, the RP 10.10.10.1 is learned on the LHR via a static configuration for the group-range 224.0.0.0/4.

If no RP is listed for the queried group, then the device does not have the RP configured. Configure the RP on the device for this specific Multicast group. For instructions, refer to  Configuring Static RP .

If you see the RP but do not see the group, verify the configuration on the RP and the group status on the RP. You can also add the group to the RP configuration. The command is:

set protocols pim rp static address <RP ip address> [group-ranges <group address>]

In the configuration below, notice that the group-range is not specified. If you do not specify the group-range, then the RP configured acts as the RP for all the groups in the range 224.0.0.0/4. If the RP is known but the Multicast group in question is not present, verify the status of the multicast group in the RP and also that there are interested receivers.

LHR

root@LHR> show configuration protocols pim | display set 
set protocols pim rp static address 10.10.10.1
set protocols pim interface ge-0/0/0.0
set protocols pim interface ge-0/0/1.0
set protocols pim interface irb.10

RP

root@RP> show configuration protocols pim | display set 
set protocols pim rp local address 10.10.10.1
set protocols pim interface all

Note:  If your LHR or RP is an SRX device, then your configuration will also have PIM enabled on the relevant security zones and security policies to allow traffic between the security zones.

Refer to steps 3 and 4 in  KB28362 - [SRX] Configuration example - Multicast PIM Sparse Mode [juniper.net]  for more information. For example, if the LHR is an SRX device, it also needs this configuration:

set security zones security-zone trust address-book address 192.168.200.0 192.168.200.0/24
set security zones security-zone trust host-inbound-traffic protocols pim
set security zones security-zone trust interfaces ge-0/0/1.0
set security zones security-zone untrust address-book address 239.255.0.1 239.255.0.1/32
set security zones security-zone untrust host-inbound-traffic protocols pim
set security zones security-zone untrust interfaces ge-0/0/0.0
set security policies from-zone trust to-zone untrust policy p1 match source-address 192.168.200.0
set security policies from-zone trust to-zone untrust policy p1 match destination-address 239.255.0.1
set security policies from-zone trust to-zone untrust policy p1 match application junos-udp-any
set security policies from-zone trust to-zone untrust policy p1 then permit

Modification History

2020-05-07: Updated links and checked article for validity and accuracy; article valid and still relevant

2022-02-28: Updated topology with a new diagram and updated outputs; links validated as well