Multicast VPN Configuration Example

In the following example (Figure 13), customer edge router 1 (CE1) and customer edge router 2 (CE2) exist in two separate VPNs. Each VPN is configured with its assigned Multicast Domain (235.1.1.1 and 235.1.1.2, respectively).

Figure 13: Multicast VPNs

To better understand the example, keep the following in mind:

• Lp is a loopback interface in the parent router. This address is the loopback interface used as the BGP peer address of the provider edge router (PE). Its address is advertised in the provider address space.
• Tv is the MTI in the VRF. This interface is typically configured as a PIM sparse-mode interface (though you can configure it for dense-mode or sparse-dense-mode). Any packets that originate in the VRF are sent using the address of this interface as the source address. You must set this interface address to be identical to loopback interface of the parent router (Lp).

  Caution: Defining the Tv interface with an address other than the loopback interface of the parent router might restrict operation with non-Juniper Networks routers.

• Tp is an unnumbered IP interface that is tied to the loopback interface of the provider edge router (PE).

To configure the example, use the following general procedures:

Note: This example provides general information for configuring a simple Multicast VPN network. For detailed information about creating GRE tunnels, see Configuring IP Tunnels in the JUNOSe IP Services Configuration Guide. For detailed information about PIM sparse-mode configuration, see PIM Sparse Mode.

1. Configure BGP/MPLS VPN.

   host1:PE2(config-router)#router bgp 100

   host1:PE2(config-router)#address-family vpnv4 unicast

   host1:PE2(config-router-af)#neighbor 1.1.1.1 activate

   host1:PE2(config-router-af)#neighbor 1.1.1.1 next-hop-self

   host1:PE2(config-router-af)#neighbor 3.3.3.3 activate

   host1:PE2(config-router-af)#neighbor 3.3.3.3 next-hop-self

   host1:PE2(config-router-af)#exit-address-family

   See Configuring BGP-MPLS Applications in the JUNOSe BGP and MPLS Configuration Guide for details.

2. Configure PIM sparse mode in the core and RP for MVPN group addresses.

   Note: For MVPN, it is a typical practice to use shared trees.

   host1:PE1(config-router)#virtual-router PE2

   host1:PE2(config)#ip multicast-routing

   host1:PE2(config)#

   host1:PE2(config)#! MDT RP is 72.72.72.72 (P1)

   host1:PE2(config)#access-list 1 permit ip 235.0.0.0 0.255.255.255 any

   host1:PE2(config)#ip pim rp-address 72.72.72.72 1

   host1:PE2(config)#

   host1:PE2(config)#! Do not switch from RPT for MDTs

   host1:PE2(config)#ip pim spt-threshold infinity group-list 1

   host1:PE2(config)#

3. Configure the loopback interface, Lp, in parent router PE2.

   host1:PE2(config)#interface loopback 0

   host1:PE2(config-if)#ip address 2.2.2.2 255.255.255.255

   host1:PE2(config-if)#ip pim sparse-mode

   host1:PE2(config-if)

   Note: You must configure the loopback interface for PIM sparse mode to support unnumbered MDTs.

4. Add PIM-SM to core-facing interfaces.

   host1:PE2(config)#interface atm2/1.20

   host1:PE2(config-subif)#ip pim sparse-mode

   host1:PE2(config-subif)#

5. Extend the BGP router configuration to contribute VPN routes into the multicast router table of the VRF using the ip route-type both command.

   host1:PE2(config)#router bgp 100

   host1:PE2(config-router)#address-family ipv4 unicast vrf PE21

   host1:PE2(config-router-af)#ip route-type both

   host1:PE2(config-router-af)#exit

   host1:PE2(config-router)#

6. Configure the GRE tunnel for VPN1.

   host1(config)#interface tunnel gre:MTI-21 transport-virtual-router PE2

   host1(config-if)#tunnel source 2.2.2.2

   host1(config-if)#tunnel destination 235.1.1.1

   host1(config-if)#tunnel mdt

   host1(config-if)#exit

   host1(config)#

7. Configure the GRE tunnel for VPN2

   host1(config)#interface tunnel gre:MTI-22 transport-virtual-router PE2

   thost1(config-if)#tunnel source 2.2.2.2

   host1(config-if)#tunnel destination 235.1.1.2

   host1(config-if)#tunnel mdt

   host1(config-if)#exit

   host1(config)#

8. Configure the IP interface (Tv) in PE2:CE1 as a PIM sparse-mode interface with the address of the loopback interface.

   host1(config)#virtual-router PE2:CE21

   host1:PE2:CE21(config)#interface tunnel gre:MTI-21

   host1:PE2:CE21(config)#ip address 2.2.2.2 255.255.255.255

   host1:PE2:CE21(config)#ip pim sparse-mode

   host1:PE2:CE21(config)#exit

   host1:PE2:CE21#

9. Configure the IP interface (Tv) in PE2:CE2 as a PIM sparse-mode interface with the address of the loopback interface (same as the loopback 0 address for PE2).

   host1:PE2:CE21(config)#interface loopback 0

   host1:PE2:CE21(config-if)#ip address 2.2.2.2 255.255.255.255

   host1:PE2:CE21(config-if)#exit

   host1:PE2:CE21(config)#exit

   host1:PE2:CE21#virtual-router PE2:CE22

   host1:PE2:CE22#configuration terminal

   host1:PE2:CE22(config)#interface tunnel gre:MTI-22

   host1:PE2:CE22(config)#ip unnumbered loopback 0

   host1:PE2:CE22(config)#ip pim sparse-mode

   host1:PE2:CE22(config)#exit

   host1:PE2:CE22#

10. Configure the Tp interfaces as unnumbered IP interfaces.

    host1(config)#interface tunnel gre:MTI-21.mdt

    host1(config-if)#ip unnumbered loopback 0

    host1(config-if)#ip pim sparse-mode

    host1(config-if)#exit

    host1(config)#

    host1(config)#interface tunnel gre:MTI-22.mdt

    host1(configif)#ip unnumbered loopback 0

    host1(config-if)#ip pim sparse-mode

    host1(config-if)#exit

    host1(config)#

tunnel mdt

• Use to enable multicast distribution tree operation so the IP tunnel component can create an MDT interface. This command functions for GRE interfaces only.
• Example

  host1(config-if)#tunnel mdt

• The no version disables MDT on the interface.
• See tunnel mdt.

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