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Configuring Provider Tunnels in MVPNs

PIM Sparse Mode, PIM Dense Mode, Auto-RP, and BSR for MBGP MVPNs

You can configure PIM sparse mode, PIM dense mode, auto-RP, and bootstrap router (BSR) for MBGP MVPN networks:

  • PIM sparse mode—Allows a router to use any unicast routing protocol and performs reverse-path forwarding (RPF) checks using the unicast routing table. PIM sparse mode includes an explicit join message, so routers determine where the interested receivers are and send join messages upstream to their neighbors, building trees from the receivers to the rendezvous point (RP).

  • PIM dense mode—Allows a router to use any unicast routing protocol and performs reverse-path forwarding (RPF) checks using the unicast routing table. Packets are forwarded to all interfaces except the incoming interface. Unlike PIM sparse mode, where explicit joins are required for packets to be transmitted downstream, packets are flooded to all routers in the routing instance in PIM dense mode.

  • Auto-RP—Uses PIM dense mode to propagate control messages and establish RP mapping. You can configure an auto-RP node in one of three different modes: discovery mode, announce mode, and mapping mode.

  • BSR—Establishes RPs. A selected router in a network acts as a BSR, which selects a unique RP for different group ranges. BSR messages are flooded using a data tunnel between PE routers.

Configuring PIM Provider Tunnels for an MBGP MVPN

To configure a Protocol Independent Multicast (PIM) sparse mode provider tunnel for a multicast VPN, include the pim-asm statement:

You can include this statement at the following hierarchy levels:

  • [edit routing-instances routing-instance-name provider-tunnel]

  • [edit logical-systems logical-system-name routing-instances routing-instance-name provider-tunnel]

To complete the PIM sparse mode provider tunnel configuration, you also need to specify the group address using the group-address option. The source address for a PIM sparse mode provider tunnel is configured to be the loopback address of the loopback interface in the inet.0 routing table.

Configuring PIM-SSM GRE Selective Provider Tunnels

This topic describes how to configure a PIM-SSM GRE selective provider tunnel for an MBGP MVPN.

Creating a selective provider tunnel enables you to move high-rate traffic off the inclusive tunnel and deliver the multicast traffic only to receivers that request it. This improves bandwidth utilization.

To configure a PIM-SSM GRE selective provider tunnel for the customer multicast group address, the customer source address, and a virtual routing instance named green:

  1. Configure the multicast group address range to be used for creating selective tunnels. The address prefix can be any valid nonreserved IPv4 multicast address range. Whether you configure a range of addresses or a single address, make sure that you configure enough group addresses for all the selective tunnels needed.
  2. Configure the threshold rate in kilobits per second (Kbps) for triggering the creation of the selective tunnel. If you set the threshold rate to zero Kbps, the selective tunnel is created immediately, and the multicast traffic does not use an inclusive tunnel at all. Optionally, you can leave the threshold rate unconfigured and the result is the same as setting the threshold to zero.
  3. Configure the autonomous system number in the global routing options. This is required in MBGP MVPNs.

When configuring PIM-SSM GRE selective provider tunnels, keep the following in mind:

  • Aggregation of multiple customer multicast routes to a single PIM S-PMSI is not supported.

  • Provider tunnel multicast group addresses must be IPv4 addresses, even in configurations in which the customer multicast group and source are IPv6 addresses.