Function
The lsp-trigger command sets a policy for establishing LDP label switched paths (LSPs).
The undo lsp-trigger command restores the default settings.
By default, LDP uses IP routes with 32-bit addresses to set up backup LSPs.
Parameters
| Parameter | Description | Value |
|---|---|---|
| all | Indicates that all static and Interior Gateway Protocol (IGP) routes trigger the establishment of LDP LSPs. | - |
| host | Indicates that 32-bit address routes trigger the establishment of LDP LSPs. | - |
| ip-prefix ip-prefix-name | Specifies the name of the IP prefix list that triggers the establishment of LDP LSPs. | The name is a string of 1 to 169 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string. |
| none | Indicates that the establishment of an LDP LSP is not triggered. | - |
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 command and the lsp-trigger bgp-label-route command are used to configure policies for triggering the LDP LSP establishment. The former command is used for static and IGP routes; the latter command is used for labeled public BGP routes.
NOTE: Using 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
The lsp-trigger command can be used to configure polices 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 command can be used to establish proxy egress LSPs. The lsp-trigger host command, however, cannot be used to establish proxy egress LSPs.