The RIB processing of specific routes can be prioritized through the use of the rib-priority command. This command allows specific routes to be prioritized through the protocol processing so that updates are propagated to the FIB as quickly as possible.
Configuring the rib-priority command either within the global OSPF or OSPFv3 routing context or under a specific OSPF/OSPFv3 interface context enables this feature. Under the global OSPF context, a prefix list can be specified that identifies which route prefixes should be considered high priority. If the rib-priority high command is configured under an OSPF interface context, all routes learned through that interface is considered high priority.
The routes that have been designated as high priority are the first routes processed and then passed to the FIB update process so that the forwarding engine can be updated. All known high priority routes should be processed before the OSPF routing protocol moves on to other standard priority routes. This feature has the most impact when a large number of routes are learned through the OSPF routing protocols.