Example: Configuring PIM Dense Mode over Layer 3 VPNs

Multicast over Layer 3 VPNs for dense mode works much the same way as in sparse mode. In the following example, the VPN network uses dense mode for the entire multicast group range. Compare this with the configuration used in Example: Configuring Any-Source Multicast for Draft-Rosen VPNs. In that configuration, sparse mode is used for the entire multicast group range.

1. Configure PIM on the P router.
   protocols {pim {dense-groups {224.0.1.39/32;224.0.1.40/32;}rp {local {address 10.255.71.47;}}interface all {mode sparse;version 2;}interface fxp0.0 {disable;}}}
2. Configure PIM on the PE router. Include the mode statement at the [edit protocols pim interface] hierarchy level to specify sparse mode.
   protocols {pim {rp {static {address 10.255.71.47;}}interface all {mode sparse;version 2;}interface fxp0.0 {disable;}}}
3. Configure PIM on the CE router. Include the mode statement at the [edit protocols pim interface] hierarchy level to specify dense mode.
   protocols {pim {interface all {mode dense;version 2;}interface fxp0.0 {disable;}}}
4. Configure dense mode in the routing instance of the PE router facing the CE router. Include the mode statement at the [edit routing-instances instance-name protocols pim] hierarchy level to specify dense mode for the CE-facing interface t1-1/0/0:0.0.
   routing-instances {VPN-A {instance-type vrf;interface t1-1/0/0:0.0;interface lo0.1;route-distinguisher 10.255.71.46:100;vrf-import VPNA-import;vrf-export VPNA-export;protocols {ospf {export bgp-to-ospf;area 0.0.0.0 {interface t1-1/0/0:0.0;interface lo0.1;}}pim {vpn-group-address 239.1.1.1;interface t1-1/0/0:0.0 {mode dense;version 2;}interface lo0.1 {mode dense;version 2;}}}}}interfaces {lo0 {description "unit 1 has the important PIM address";unit 0 {family inet {address 192.168.27.13/32;primary;address 127.0.0.1/32;}}unit 1 {family inet {address 10.10.47.101/32;}}}}

For information about configuring VPNs, see the Junos VPNs Configuration Guide.