Related Documentation
- M, MX, T Series
- Configuring Point-to-Multipoint LSPs for an MBGP MVPN
- M, MX, PTX, T Series
- Point-to-Multipoint LSPs Overview
Example: Configuring Point-to-Multipoint LDP LSPs as the Data Plane for Intra-AS MBGP MVPNs
This example shows how to configure point-to-multipoint (P2MP) LDP label-switched paths (LSPs) as the data plane for intra-autonomous system (AS) multiprotocol BGP (MBGP) multicast VPNs (MVPNs). This feature is well suited for service providers who are already running LDP in the MPLS backbone and need MBGP MVPN functionality.
Requirements
Before you begin:
- Configure the router interfaces. See the Junos OS Network Interfaces Library for Routing Devices.
- Configure an interior gateway protocol or static routing. See the Junos OS Routing Protocols Library for Routing Devices.
- Configure a BGP-MVPN control plane. See MBGP-Based Multicast VPN Trees in the Multicast Protocols Feature Guide for Routing Devices.
- Configure LDP as the signaling protocol on all P2MP provider and provider-edge routers. See LDP Operation in the Junos OS MPLS Applications Library for Routing Devices.
- Configure P2MP LDP LSPs as the provider tunnel technology on each PE router in the MVPN that belongs to the sender site set. See the Junos OS MPLS Applications Library for Routing Devices.
- Configure either a virtual loopback tunnel interface (requires a Tunnel PIC) or the vrf-table-label statement in the MVPN routing instance. If you configure the vrf-table-label statement, you can configure an optional virtual loopback tunnel interface as well.
- In an extranet scenario when the egress PE router belongs to multiple MVPN instances, all of which need to receive a specific multicast stream, a virtual loopback tunnel interface (and a Tunnel PIC) is required on the egress PE router. See Configuring Virtual Loopback Tunnels for VRF Table Lookup and Junos Services Interfaces Configuration Guide in the in the Junos OS Services Interfaces Library for Routing Devices.
- If the egress PE router is also a transit router for the point-to-multipoint LSP, a virtual loopback tunnel interface (and a Tunnel PIC) is required on the egress PE router. See Configuring Virtual Loopback Tunnels for VRF Table Lookup and Junos Services Interfaces Configuration Guide in the Junos OS Services Interfaces Library for Routing Devices.
- Some extranet configurations of MBGP MVPNs with point-to-multicast
LDP LSPs as the data plane require a virtual loopback tunnel interface
(and a Tunnel PIC) on egress PE routers. When an egress PE router
belongs to multiple MVPN instances, all of which need to receive a
specific multicast stream, the vrf-table-table statement
cannot be used. In Figure 1, the CE1
and CE2 routers belong to different MVPNs. However, they want to receive
a multicast stream being sent by S. If the vrf-table-label statement is configured on Router PE2, the packet cannot be forwarded
to both CE1 and CE2. This causes packet loss. The packet is forwarded
to both Routers CE1 and CE2 if a virtual loopback tunnel interface
is used in both MVPN routing instances on Router PE2.
Figure 1: Extranet Configuration of MBGP MVPN with P2MP LDP LSPs as Data Plane
Overview
This example shows how to configure P2MP LSP LSPs as the data plane for intra-AS selective provider tunnels. Selective P2MP LSPs are triggered only based on the bandwidth threshold of a particular customer’s multicast stream. A separate P2MP LDP LSP is set up for a given customer source and customer group pair (C-S, C-G) by a PE router. The C-S is behind the PE router that belongs in the sender site set. Aggregation of intra-AS selective provider tunnels across MVPNs is not supported.
When you configure selective provider tunnels, leaves discover the P2MP LSP root as follows. A PE router with a receiver for a customer multicast stream behind it needs to discover the identity of the PE router (and the provider tunnel information) with the source of the customer multicast stream behind it. This information is auto-discovered dynamically using the S-PMSI AD routes originated by the PE router with the C-S behind it.
The Junos OS also supports P2MP LDP LSPs as the data plane for intra-AS inclusive provider tunnels. These tunnels are triggered based on the MVPN configuration. A separate P2MP LSP LSP is set up for a given MVPN by a PE router that belongs in the sender site set. This PE router is the root of the P2MP LSP. Aggregation of intra-AS inclusive provider tunnels across MVPNs is not supported.
When you configure inclusive provider tunnels, leaves discover the P2MP LSP root as follows. A PE router with a receiver site for a given MVPN needs to discover the identities of PE routers (and the provider tunnel information) with sender sites for that MVPN. This information is auto-discovered dynamically using the intra-AS auto-discovery routes originated by the PE routers with sender sites.
Figure 2 shows the topology used in this example.
Figure 2: P2MP LDP LSPs as the Data Plane for Intra-AS MBGP MVPNs

In Figure 2, the routers perform the following functions:
- R1 and R2 are provider (P) routers.
- R0, R3, R4, and R5 are provider edge (PE) routers.
- MBGP MVPN is configured on all PE routers.
- Two VPNs are defined: green and red.
- Router R0 serves both green and red CE routers in separate routing instances.
- Router R3 is connected to a green CE router.
- Router R5 is connected to overlapping green and red CE routers in a single routing instance.
- Router R4 is connected to overlapping green and red CE routers in a single routing instance.
- OSPF and multipoint LDP (mLDP) are running in the core.
- Router R1 is a route reflector (RR), and router R2 is a redundant RR.
- Routers R0, R3, R4, and R5 are client internal BGP (IBGP) peers.
Configuration
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.
To configure P2MP LDP LSPs as the data plane for intra-AS MBGP MVPNs:
Configure LDP on all routers.
[edit protocols ldp]user@host# set interface fe-0/2/1.0user@host# set interface fe-0/2/3.0user@host# set p2mpConfigure the provider tunnel.
[edit routing-instance red ]user@host# set instance-type mvpnuser@host# set interface vt-0/1/0.1user@host# set interface lo0.1user@host# set route-distinguisher 10.254.1.1:1user@host# set provider-tunnel ldp-p2mpConfigure the selective provider tunnel.
user@host# set provider-tunnel selective group 224.1.1.1/32 source 192.168.1.1/32 ldp-p2mpIf you are done configuring the device, commit the configuration.
user@host# commit
Results
From configuration mode, confirm your configuration by entering the show protocols and show routing-intances commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.
Verification
To verify the configuration, run the following commands:
- ping mpls ldp p2mp to ping the end points of a P2MP LSP.
- show ldp database to display LDP P2MP label bindings and to ensure that the LDP P2MP LSP is signaled.
- show ldp session detail to display the LDP capabilities exchanged with the peer. The Capabilities advertised and Capabilities received fields should include p2mp.
- show ldp traffic-statistics p2mp to display the data traffic statistics for the P2MP LSP.
- show mvpn instance, show mvpn neighbor, and show mvpn c-multicast to display multicast VPN routing instance information and to ensure that the LDP P2MP LSP is associated with the MVPN as the S-PMSI.
- show multicast route instance detail on PE routers to ensure that traffic is received by all the hosts and to display statistics on the receivers.
- show route label label detail to display the P2MP forwarding equivalence class (FEC) if the label is an input label for an LDP P2MP LSP.
Related Documentation
- M, MX, T Series
- Configuring Point-to-Multipoint LSPs for an MBGP MVPN
- M, MX, PTX, T Series
- Point-to-Multipoint LSPs Overview
Published: 2013-08-13
Related Documentation
- M, MX, T Series
- Configuring Point-to-Multipoint LSPs for an MBGP MVPN
- M, MX, PTX, T Series
- Point-to-Multipoint LSPs Overview