Enabling PIM Dense

PIM must be enabled globally and PIM Dense Mode (PIM DM) enabled locally on specific interfaces.

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 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.

  1. Enter global configuration mode. 
    device# configure terminal
  2. Globally enable PIM. 
    device(config)# router pim
  3. Exit to global configuration mode. 
    device(config-pim-router)# exit
  4. Enter interface configuration mode. 
    device(config)# interface ethernet 1/1/3
    This step configures Ethernet interface 1/1/3 and this interface is to run PIM DM.
  5. Enter the IP address for the interface. 
    device(config-if-e10000-1/1/3)# ip address 10.9.9.9/32
  6. Configure PIM DM on the interface. 
    device(config-if-e10000-1/1/3)# ip pim

The following example enables PIM globally and PIM DM on Ethernet interface 1/1/3. 

device# configure terminal
device(config)# router pim
device(config-pim-router)# interface ethernet 1/1/3
device(config-if-e10000-1/1/3)# ip address 207.95.5.1/24
device(config-if-e10000-1/1/3)# ip pim
Parent topic: PIM Dense