Enabling PIM Dense on a Specific VRF

PIM must be enabled globally and PIM Dense Mode (PIM DM) can be enabled for a specific virtual routing and forwarding instance (VRF).

By default, PIM is disabled. To enable PIM:

  • Enable the feature globally.
  • Configure the IP interfaces that will use PIM.
  • Enable PIM DM locally on the ports that have the IP interfaces you configured for PIM.

A use case for PIM DM can be to initiate the use of desktop video for fellow users on a sprawling campus network. All destination workstations have the appropriate hardware and software but the devices that connect the various buildings need to be configured to support PIM multicasts from the designated video conference server, as illustrated in the Pruning a Multicast Tree section. In this section, PIM is enabled on each of the devices shown in the “Pruning leaf nodes from a multicast tree” figure, on which multicasts are expected. You can enable PIM on each device independently or remotely from one of the devices with a Telnet connection. Follow the same steps for each device. All changes are dynamic.

All PIM parameters available for the default device instance are configurable for a VRF-based PIM instance.

  1. Enter global configuration mode. 
    device# configure terminal
  2. Enable PIM for a specific VRF. 
    device(config)# router pim vrf blue
    In this example, PIM is enabled for the VRF named blue. The VRF must be created before you specify it in this task step or you will receive an error message stating that the VRF does not exist.

The following example enables PIM for the VRF named blue. 

device# configure terminal
device(config)# router pim vrf blue
Parent topic: PIM Dense