Configuring PIM and the VPN Group Address in a Routing Instance

The configuration syntax for PIM in a Layer 3 instance is available at the [edit routing-instances protocols pim] hierarchy level. It is similar to the global PIM configuration syntax found at the [edit protocols pim] hierarchy level.

In Junos OS Release 5.3 and later, you can include the vpn-group-address statement at the [edit routing-instances instance-name protocols pim] hierarchy level. You include this statement within the routing instance and specify the multicast group address for a particular VPN. Only one vpn-group-address statement can be configured per VPN, and this address should be unique on a per-VPN basis. To review how the VPN group address is used within GRE packet headers, see Stage 2 in Dual PIM Multicast VPNs: Draft Rosen.

Keep in mind that each PE router contains two entries of PIM: one for the master instance of PIM that connects through the service provider network and a second for the routing instance that connects to the CE router. The RP listed within the routing instance is the VPN C-RP, whereas the RP in the master PIM instance is an SP-RP. The following sample configuration shows a PE router with PIM enabled for sparse-dense mode in the VPN instance.

Note: You cannot configure PIM within a nonforwarding instance. If you try to do so, the router displays a commit check error and does not complete the configuration commit process.

Note: In Junos OS Release 5.5 and later, you can configure PIM dense mode with the dense statement at the [edit routing-instances pim mode] hierarchy level. Sparse mode is available at this same hierarchy level in Junos OS Release 5.3 and later.