The prefix-priority command sets the convergence priority of OSPF routes.
The undo prefix-priority command restores the default convergence priority of OSPF routes.
By default, the convergence priority of public 32-bit host routes is medium, and the convergence of other OSPF routes is low.
prefix-priority { critical | high | medium } ip-prefix ip-prefix-name
undo prefix-priority { critical | high | medium }
| Parameter | Description | Value |
|---|---|---|
| critical | Sets the convergence priority of OSPF routes to critical. | - |
| high | Sets the convergence priority of OSPF routes to high. | - |
| medium | Sets the convergence priority of OSPF routes to medium. | - |
| ip-prefix | Matches OSPF routes according to the IP prefix list. | - |
| ip-prefix-name | Specifies the name of an IP prefix list. | The value is a string of 1 to 169 case-sensitive characters and cannot contain a space. |
Usage Scenario
This command sets the convergence priority of OSPF routes based on the specified name of the IP prefix list, and takes effect on the public network only.
After the prefix-priority command is run, OSPF route calculation, LSA flooding, and LSDB synchronization can be implemented based on the configured priority. Therefore, route convergence speeds up.
Configuration Impact
When an LSA matches multiple policy priorities, the highest priority takes effect.
OSPF calculates LSAs in the sequence of intra-area routes, inter-area routes, and AS external routes. After this command is run, OSPF calculates the three types of routes separately based on the specified route calculation priorities. The sequence of convergence priorities is critical > high > medium > low. To speed up the processing of LSAs with a high priority, the LSAs need to be placed, based on the priorities, into critical, high, medium, and low queues during LSA flooding.
Precautions
By default, the convergence priority of public OSPF host routes is medium, the convergence priority of direct routes is high, the convergence priority of static routes is medium, and the convergence priority of the routes of other protocols, such as BGP and RIP, is low. On the private network, OSPF 32-bit host routes are globally identified as medium.