lsp-trigger

Function

The lsp-trigger command sets a policy for establishing LDP LSPs.

The undo lsp-trigger command restores the default setting.

By default, LDP uses IP host routes with 32-bit addresses (excluding host routes with 32-bit interface addresses) to establish LSPs.

Format

lsp-trigger { all | host | ip-prefix ip-prefix-name | none }

undo lsp-trigger

Parameters

Parameter	Description	Value
all	Indicates that all static and IGP routes trigger the establishment of LSPs.	-
host	Indicates that IP host routes with 32-bit addresses (excluding host routes with 32-bit interface addresses) trigger the establishment of LSPs.	-
ip-prefix ip-prefix-name	Specifies the name of the IP prefix list that triggers the establishment of LSPs.	The value is an existing IP prefix list name.
none	Indicates that the establishment of an LSP is not triggered.	-

Views

MPLS view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

After MPLS LDP is enabled, LSPs are automatically established. If no policy is configured, an increasing number of LSPs are established, wasting resources.

The lsp-trigger command configures a policy to allow LDP to use specified routes to establish LSPs. This setting prevents unwanted LSPs from being established and helps reduce resource wastes.

The lsp-trigger all command is not recommended. If this command is run, LDP uses all IGP routes to establish LSPs, causing a large number of unwanted LSPs to be established and wasting system resources. Before using this command, configure a policy for filtering out routes unnecessary for the LSP establishment. The policy helps reduce the number of LSPs to be established and save system resources.

Prerequisites

MPLS has been enabled globally using the mpls (system view) command.

Precautions

Modifying the LSP-triggering policy during the LDP GR period is invalid.
The lsp-trigger command can be used to configure policies only for ingress and egress LSPs on the public network and ingress and egress LSPs on the private network that are established using IGP routes. To configure a policy for triggering the transit LSP establishment, run the propagate mapping command.
The lsp-trigger host command can be run on either of the following nodes to provide a specific function:
- Ingress: This command enables the ingress to use all routes with a 32-bit mask to establish LDP LSPs.
- Egress: This command enables the egress to use local routes with a 32-bit mask to establish LDP LSPs.
The lsp-trigger { all | ip-prefix ip-prefix-name } command can be used to establish proxy egress LSPs. The lsp-trigger host command, however, cannot be used to establish proxy egress LSPs.
Creating an IP prefix list before it is referenced is recommended. By default, nonexistent IP prefix lists cannot be referenced using the command. If the route-policy nonexistent-config-check disable command is run in the system view and a nonexistent IP prefix list is referenced using the current command, all static and IGP routes trigger LDP LSP establishment.

Example

# Trigger the establishment of LSPs based on all static and IGP routes.

<HUAWEI> system-view
[HUAWEI] mpls
[HUAWEI-mpls] lsp-trigger all