mpls te priority
Function
The mpls te priority command configures the setup priority and holding priority for an MPLS TE tunnel.
The undo mpls te priority command restores the default settings.
The default setup and holding priority for an MPLS TE tunnel are both 7.
Parameters
| Parameter | Description | Value |
|---|---|---|
| setup-priority | Specifies the setup priority. | The value is an integer that ranges from 0 to 7. The smaller the value, the higher the priority. |
| hold-priority | Specifies the holding priority. | The value is an integer that ranges from 0 to 7. The smaller the value, the higher the priority. Its value is the same as the setup priority by default. |
Usage Guidelines
Usage Scenario
If bandwidth resources on a link cannot satisfy the requirements for establishing all CR-LSPs, you can specify the setup and holding priorities for certain CR-LSPs. In this manner, the CR-LSPs with higher priorities can be established by preempting bandwidth resources of CR-LSPs with lower priorities before transmitting certain user services.
Priorities of a CR-LSP consist of the setup priority and holding priority, representing the preemption relationship between a CR-LSP to be established and an established CR-LSP. If the setup priority of a CR-LSP to be established is higher than the holding priority of an established CR-LSP, the CR-LSP to be established can preempt the bandwidth resources of the established one.
The default setup and holding priorities of CR-LSPs are 7, the lowest priority value. Default priorities take effect on all CR-LSPs if no priorities are specified. These CR-LSPs with the default priorities are at the risk of being preempted by those with higher priorities.
Precautions
During the planning of a network, it is recommended that the setup and holding priorities of all CR-LSPs be strictly planned. To preferentially transmit services over a CR-LSP, you can set the higher setup and holding priorities for the CR-LSP, preventing unwanted bandwidth preemption. The same setup and holding priorities are set for CR-LSPs which are transmitting services with the same priority, also preventing bandwidth preemption.
In addition, on one TE tunnel, its setup priority must be less than or equal to its holding priority. This ensures that CR-LSPs in the tunnel can be successfully set up, and prevents CR-LSP flapping caused by bandwidth preemption between CR-LSPs.
After the priorities of an existing CR-LSP have been changed, the existing CR-LSP will be deleted and a new one will be established. Therefore, back up CR-LSPs with lower priorities before setting higher priorities for a certain CR-LSP.