Enabling Next-Generation MVPN Services
Juniper Networks introduced the industry’s first implementation of BGP next-generation multicast virtual private networks (MVPNs). See Figure 1 for a summary of a Junos OS next-generation MVPN routing flow.
Next-generation MVPN services are configured on top of BGP-MPLS unicast VPN services.
You can configure a Juniper Networks PE router that is already providing unicast BGP-MPLS VPN connectivity to support multicast VPN connectivity in three steps:
- Configure the provider edge (PE) routers to support the BGP multicast VPN address family by including the signaling statement at the [edit protocols bgp group group-name family inet-mvpn] hierarchy level. This address family enables PE routers to exchange MVPN routes.
- Configure the PE routers to support the MVPN control plane tasks by including the mvpn statement at the [edit routing-instances routing-instance-name protocols] hierarchy level. This statement signals PE routers to initialize the MVPN module that is responsible for the majority of next-generation MVPN control plane tasks.
- Configure the sender PE router to signal a provider tunnel by including the provider-tunnel statement at the [edit routing-instances routing-instance-name] hierarchy level. You must also enable the tunnel signaling protocol (RSVP-TE or P-PIM) if it is not part of the unicast VPN service configuration. To enable the tunnel signaling protocol, include the rsvp-te or pim-asm statements at the [edit routing-instances routing-instance-name provider-tunnel] hierarchy level.
After these three statements are configured and each PE router has established internal BGP (IBGP) sessions using both INET-VPN and MCAST-VPN address families, four routing tables are automatically created. These tables are bgp.l3vpn.0, bgp.mvpn.0, <routing-instance-name>.inet.0, and <routing-instance-name>.mvpn.0. See Table 1
Table 1: Automatically Generated Routing Tables
Automatically Generated Routing Table
Populated with VPN-IPv4 routes received from remote PE routers via the INET-VPN address family. The routes in the bgp.l3vpn.0 table are in the form of RD:IPv4-address and carry one or more routing table communities. In a next-generation MVPN network, these routes also carry rt-import and src-as communities.
Populated by MVPN routes (Type 1 – Type 7). Received from remote PE routers via the MCAST-VPN address family. Routes in this table carry one or more routing table communities.
Populated by local and remote VPN unicast routes. The local VPN routes are typically learned from local CE routers via protocols such as BGP, OSPF, and RIP, or via a static configuration. The remote VPN routes are imported from the bgp.l3vpn.0 table if their routing table matches one of the import routing tables configured for the VPN. When remote VPN routes are imported from the bgp.l3vpn.0 table, their route distinguisher is removed, leaving them as regular unicast IPv4 addresses.
Populated by local and remote MVPN routes. The local MVPN routes are typically the locally originated routes, such as Type 1 intra-AS autodiscovery routes, or Type 7 C-multicast routes. The remote MVPN routes are imported from the bgp.mvpn.0 table based on their route target. The import route target used for accepting MVPN routes into the <routing-instance-name>.mvpn.0 table is different for C-multicast MVPN routes (Type 6 and Type 7) versus non-C-multicast MVPN routes (Type 1 – Type 5).