Example: Configuring PIM Sparse-Dense Mode over Layer 3 VPNs

Multicast over Layer 3 VPNs for sparse-dense mode works much the same way as in sparse mode. In the following example, the VPN network uses dense mode for group range 229.0.0.0/8 and sparse mode for the remaining multicast group range outside 229.0.0.0/8. Compare this with the configuration used in Example: Configuring PIM Sparse Mode over Layer 3 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 sparse-dense mode for the PE router interfaces by including the mode statement at the [edit protocols pim interface] hierarchy level.
   protocols {pim {rp {static {address 10.255.71.47;}}interface all {mode sparse-dense;version 2;}interface fxp0.0 {disable;}}}
3. Configure PIM on the CE router. Include the dense-groups statement at the [edit protocols pim] hierarchy level to define the desired dense groups address range on the CE router. Include the mode statement at the [edit protocols pim interface] hierarchy level to specify sparse-dense mode.
   protocols {pim {dense-groups {229.0.0.0/8;}rp {static {address 10.255.245.91;}}interface all {mode sparse-dense;version 2;}interface fxp0.0 {disable;}}}
4. Include the dense-groups statement at the [edit routing-instances instance-name protocols pim] hierarchy level to define the desired dense groups address range for the routing instance on the PE router. Include the mode statement at the [edit routing-instances instance-name pim interface] hierarchy level to specify sparse-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 {dense-groups {229.0.0.0/8;}vpn-group-address 239.1.1.1;rp {static {address 10.255.245.91;}}interface t1-1/0/0:0.0 {mode sparse-dense;version 2;}interface lo0.1 {mode sparse-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.