How to configure and verify the group-specific rendezvous point for multicast on FortiGate

akileshc · ‎06-14-2023

Description

This article describes that Group-specific RP multicast is a method used in multicast networking to designate a specific rendezvous point (RP) for a particular multicast group. In traditional multicast routing protocols, all multicast traffic is directed to a single RP. However, in group-specific RP multicast, different multicast groups can have their own designated RP.

By configuring group-specific RP multicast, network administrators can optimize multicast traffic management and improve efficiency. Each multicast group can be assigned a dedicated RP, allowing for better control over multicast forwarding and reducing the load on the RP.

This approach allows for more flexibility in multicast deployments, particularly in scenarios where different multicast groups have varying requirements or need to be isolated from each other.

Group-specific RP multicast helps improve scalability and enables efficient delivery of multicast traffic in complex network environments.

Scope

FortiGate.

Solution

To configure a group-specific rendezvous point for multicast on FortiGate, please follow the instructions below:

Access the FortiGate CLI or web interface.
Identify the multicast group to configure a group-specific rendezvous point.
Configure an access-list including the specific multicast group IP address

config router access-list
edit "MC_group1"
config rule
edit 1
set prefix 239.0.0.5 255.255.255.255 -> Multicast Group IP address.
next
end

4. Configure the group-specific rendezvous point(RP) using the following command:

config router multicast
set multicast-routing enable
config pim-sm-global
config rp-address
  edit 1
  set ip-address 1.1.1.1 <----- RP router address.
set group "MC_group1" <----- Groups to use this RP (access list name)
  next
end

5. Verify the rp-mapping using the command:

get router info multicast pim sparse-mode rp-mapping
PIM Group-to-RP Mappings
Group(s): 239.0.0.5/32, Static
RP: 1.1.1.1
Uptime: 00:24:06

Note:

Ensure that the RP address is correctly set for the desired multicast group.

Once the group-specific rendezvous point is configured, monitor the multicast traffic to ensure that it is being correctly forwarded through the specified RP address for the respective multicast group.