# Configuring PIM Sparse Mode Remote Neighbors

You must use PIM sparse mode remote neighbors to run multicast services over BGP/MPLS VPNs.

| Note: Although you can configure PIM sparse mode remote neighbors, you can not use these remote neighbors for BGP/MPLS VPNs.

To configure a pair of E Series routers to act as PIM remote neighbors:

1. On one router, specify the other router to be a remote neighbor, and identify the IP address of the interface on the other router that is used for the connection to this router.
   host1(config-router):boston#remote-neighbor 1001::1 sparse-mode
2. Specify the location of the local interface whose address is used as the source address for the PIM connection to a remote neighbor.
   host1(config-router-rn):boston#update-source atm 2/1.108
3. (Optional) Specify how often the router sends hello messages to the remote neighbor.
   host1(config-router-rn):boston#query-interval 40
4. Repeat Steps 2 to 3 for the other router.

query-interval

- Use to specify how often the router sends hello messages to remote neighbors.
- Example
  host1(config-router-rn)#query-interval 40
- Use the no version to restore the default setting, 30 seconds.
- See query-interval.

remote-neighbor

- Use to specify a remote neighbor for PIM sparse mode.
- Specify the IP address of the interface on the remote neighbor that PIM uses as the source address for the connection to this router.
- Example
  host1(config-router)#remote-neighbor 1001::1 sparse-mode
- Use the no version to remove the remote neighbor and any attributes configured for the remote neighbor.
- See remote-neighbor.

update-source

- Use to specify the PIM interface whose local address is used as the source address for the PIM connection to a remote neighbor.
- You can use the same source address to form neighbor adjacencies with more than one PIM remote neighbor.
- You must use the IPv6 address of this interface when issuing the remote-neighbor command on the remote neighbor.
- Example
  host1(config-router-rn)#update-source loopback 5
- Use the no version to delete the source address from the connection to the remote neighbor.

  Configuration Example

This example uses the configuration shown in Figure 21. Two E Series routers called router Boston and router Chicago are running PIM and are connected by MPLS tunnels. To configure the routers as PIM remote neighbors:

1. Specify that router Chicago will be a remote neighbor of router Boston, and identify the IP address on router Chicago that will transmit datagrams to router Boston.
   boston(config-router)#remote-neighbor 1001::1 sparse-mode
2. Specify the location of the interface that will transmit datagrams from router Boston to router Chicago.
   boston(config-router-rn)#update-source atm 2/1.108
3. Specify that router Boston will send hello messages to router Chicago every 40 seconds.
   boston(config-if)#ipv6 pim query-interval 40
4. Specify that router Boston will be a remote neighbor of router Chicago, and identify the IP address on router Boston that will transmit datagrams to router Chicago.
   chicago(config-router)#remote-neighbor 2001::1 sparse-mode
5. Specify the location of the interface that will transmit datagrams from router Chicago to router Boston.
   chicago(config-router-rn)#update-source atm 2/1.95
6. Specify that router Chicago will send hello messages to router Boston every 40 seconds.
   chicago(config-if)#ipv6 pim query-interval 40
7. See update-source.