(Optional) Configuring a Policy for Triggering LSP Establishment

A policy can be configured to enable LDP to use eligible routes to establish LSPs.

Context

To establish ingress and egress LSPs on a public network, configure a policy to enable LDP to use eligible routes to establish LSPs.

A policy for triggering LSP establishment can be configured in either the MPLS view or MPLS LDP IPv4 view. If this configuration is performed in both views, the configuration in the MPLS LDP IPv4 view takes effect.

An LSP can be established only when each LSR along the LSP has a route matching a specific FEC for the LSP.

Procedure

Configure the policy for triggering LSP establishment in the MPLS view.
1. Run system-view
  The system view is displayed.
2. Run mpls
  The MPLS view is displayed.
3. Run lsp-trigger { all | host | ip-prefix prefix-name | none }
  A policy for triggering LSP establishment is configured. Any of the following parameters can be configured:
  - all: allows LDP to use IGP routes and static routes to establish LSPs. Neither public network BGP routes nor default routes can be used to establish LSPs.
  - ip-prefix: allows LDP to use FECs filtered by an IP address prefix list to establish LSPs.
  - none: disables LDP from establishing LSPs.
  If the triggering policy is changed from all to host, the LSPs that have been established using host routes are not reestablished.
4. Run proxy-egress disable
  A policy for triggering proxy egress LSP establishment is configured.
  
  If a policy allows a device to use all static and IGP routes to establish LSPs or use an IP address prefix list to establish LSPs, the policy also triggers proxy egress LSP establishment. However, the proxy egress LSPs may be unavailable, which wastes system resources. To prevent this problem, run the proxy-egress disable command to disable a device from establishing such proxy egress LSPs.
5. Run commit
  The configurations are committed.
Configure the policy for triggering LSP establishment in the MPLS LDP IPv4 view.
1. Run system-view
  The system view is displayed.
2. Run mpls
  The MPLS view is displayed.
3. Run proxy-egress disable
  A policy for triggering proxy egress LSP establishment is configured.
  
  If a policy allows a device to use all static and IGP routes to establish LSPs or use an IP address prefix list to establish LSPs, the policy also triggers proxy egress LSP establishment. However, the proxy egress LSPs may be unavailable, which wastes system resources. To prevent this problem, run the proxy-egress disable command to disable a device from establishing such proxy egress LSPs.
4. Run quit
  The system view is displayed.
5. Run mpls ldp
  The MPLS-LDP view is displayed.
6. Run ipv4-family
  The MPLS LDP IPv4 view is displayed.
7. Run lsp-trigger { all | host | ip-prefix prefix-name | none }
  A policy for triggering LSP establishment is configured. Any of the following parameters can be configured:
  - all: allows LDP to use IGP routes to establish LSPs. In addition, neither public network BGP routes nor default routes can be used to establish LSPs.
  - ip-prefix: allows LDP to use FECs filtered by an IP address prefix list to establish LSPs.
  - none: disables LDP from establishing LSPs.
  If the triggering policy is changed from all to host, the LSPs that have been established using host routes are not reestablished.
8. Run commit
  The configurations are committed.