Configuring LDP over TE

The LDP over TE function applies to the network on which core devices support TE, whereas edge devices support LDP. A TE tunnel functions as one hop of the entire LDP LSP.

Usage Scenario

LDP over TE is a technique used to establish LDP LSPs established across an RSVP TE domain and provide services for a VPN. To deploy MPLS TE on a network transmitting VPN services, a carrier has difficulties in deploying TE on an entire network. The carrier can plan a core area in which TE is deployed, and implement LDP on PEs on the edge of the TE area.

Pre-configuration Tasks

Before configuring LDP over TE, complete the following tasks:

Configure an IGP to ensure connectivity between LSRs on the network layer.
Enable MPLS on each LSR and interface.
Enable MPLS LDP on each LSR on the edge of the TE area and each interface outside the TE area.
Establish an RSVP-TE tunnel along the TE nodes.
Assign an IP address to the tunnel.
Configure virtual TE interfaces.

Configuring Forwarding Adjacency: The forwarding adjacency is configured on the ingress of a CR-LSP. The forwarding adjacency allows a route of a CR-LSP to be advertised to neighbors so that these neighbors can use this CR-LSP to transmit traffic.

Creating Remote LDP Peers on Both Ends of a TE Tunnel: Configure nodes on both ends of a TE tunnel as remote LDP peers.

(Optional) Configuring a Policy for Triggering LSP Establishment: A policy can be configured to enable LDP to use eligible routes to establish LSPs.

Verifying the LDP over TE Configuration: After configuring LDP over TE, you can view information about an LDP LSP on the ingress.