Using LDP for VPN Signaling

To use Label Distribution Protocol (LDP) for VPN signaling, perform the following steps on the PE and provider (P) routers:

1. Configure LDP on the interfaces in the core of the service provider’s network by including the ldp statement at the [edit protocols] hierarchy level. You need to configure LDP only on the interfaces between PE routers or between PE and P routers. You can think of these as the “core-facing” interfaces. You do not need to configure LDP on the interface between the PE and customer edge (CE) routers.
   [edit]

   protocols {

   ldp {

   interface type-fpc/pic/port;

   }

   }

2. Configure the MPLS address family on the interfaces on which you enabled LDP (the interfaces you configured in Step 1) by including the family mpls statement at the [edit interfaces type-fpc/pic/port unit logical-unit-number] hierarchy level:
   [edit]

   interfaces {

   type-fpc/pic/port {

   unit logical-unit-number {

   family mpls;

   }

   }

   }

3. Configure Open Shortest Path First (OSPF) or Intermediate System-to-Intermediate System (IS-IS) on each PE and P router. You configure these protocols at the master instance of the routing protocol, not within the routing instance used for the VPN.

   To configure OSPF, include the ospf statement at the [edit protocols] hierarchy level. At a minimum, you must configure a backbone area on at least one of the router’s interfaces.

   [edit]

   protocols {

   ospf {

   area 0.0.0.0 {

   interface type-fpc/pic/port;

   }

   }

   }

   To configure IS-IS, include the isis statement at the [edit protocols] hierarchy level and configure the loopback interface and International Organization for Standardization (ISO) family at the [edit interfaces] hierarchy level. At a minimum, you must enable IS-IS on the router, configure a network entity title (NET) on one of the router’s interfaces (preferably the loopback interface, lo0), and configure the ISO family on all interfaces on which you want IS-IS to run. When you enable IS-IS, Level 1 and Level 2 are enabled by default. The following is the minimum IS-IS configuration. In the address statement, address is the NET.

   [edit]

   interfaces {

   lo0 {

   unit logical-unit-number {

   family iso {

   address address;

   }

   }

   }

   type-fpc/pic/port {

   unit logical-unit-number {

   family iso;

   }

   }

   }

   protocols {

   isis {

   interface all;

   }

   }

   For more information about configuring OSPF and IS-IS, see the JUNOS Routing Protocols Configuration Guide.