Configure MPLS LSPs Using LDP

To use the Label Distribution Protocol (LDP) to configure the MPLS LSPs, perform the following steps on the PE and provider 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 provider routers. You can think of these as the "core-facing" interfaces.

[edit]

protocols {

    ldp {

        interface  interface-name;

    }

}

2. Configure the MPLS address family on the interfaces on which you enabled LDP (the interfaces you configured in Step 1):

[edit]

interfaces {

    interface-name {

        unit logical-unit-number {

            family mpls ;

        }

    }

}

Specify the interface name in the format type-fpc/pic/port.

3. Configure Open Shortest Path First (OSPF) or IS-IS on each PE and provider 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 interface-name ; 

        } 

    }

} 

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 detailed information about how to configure LDP, see the JUNOS Internet Software Configuration Guide: MPLS Applications. For more information about configuring OSPF and IS-IS, see the JUNOS Internet Software Configuration Guide: Routing and Routing Protocols.