Configuring a Priority for a Signaled LSP

The priority determines the relative importance of the LSP during setup or preemption.

The user can specify a priority for each signaled LSP for which this is the ingress LER. The priority for an LSP has two components the setup priority and the hold priority.

When multiple LSPs are enabled at the same time, such as when the device is booted, LSPs that have a higher setup priority are enabled before LSPs that have a lower setup priority.

When an LSP is assigned a high setup priority, it may preempt an LSP that is already established, causing resources assigned to the lower priority LSP to be diverted to the higher priority LSP. The hold priority specifies how likely an established LSP is to give up its resources to another LSP. To be preempted, an LSP must have a lower hold priority than the preempting LSPs setup priority. In addition, an established LSP can be preempted by a higher priority LSP only if it would allow the higher priority LSP to be established successfully.

To configure LSP 'tunnel1' with a setup priority of 6 and hold priority of 1, complete the following steps.

Enable the device for configuration.
```
device# configure
```
Enable the MPLS router.
```
device(config)# router mpls
```
Enable and configure the label switched path (LSP).
```
device(config-router-mpls)# lsp tunnel1
```
In this example, the LSP selected is named 'tunnel1'.
Configure setup and hold priorities.
```
device(config-router-mpls-lsp-tunnel1)# priority 6 1
```
In this example, the setup priority is configured to 6 and the hold priority is configured at 1. The LSP setup priority must be lower than or equal to the hold priority.

Example

In the following example, the configures LSP 'tunnel1' with a setup priority of 6 and hold priority of 1.

device# configure 
device(config)# router mpls
device(config-router-mpls)# lsp tunnel1
device(config-router-mpls-lsp-tunnel1)# priority 6 1