What action does an OSPF router take upon receiving an LSU?

When an OSPF router receives a Link State Update (LSU), the router updates its link-state database with the information contained in the LSU. The primary purpose of the LSU is to share information about the state of the links and routes with neighboring routers to allow them to compute the best path for routing packets.

Upon receiving the LSU, the router evaluates the information to determine if the received link-state information is more current or relevant compared to its existing database entries. If the information is deemed valid and represents a change or update, the router will incorporate this new data into its database. Subsequently, if the router decides that the new information warrants further updates to its neighbors, it may propagate the LSU to those neighbors, thereby ensuring that the OSPF network has a consistent view of the network topology.

This process is essential in OSPF for maintaining routing efficiency and accuracy across dynamically changing network environments. By continuously updating its database and sharing updates with other routers, OSPF ensures that all routers have a synchronized understanding of the network, which facilitates optimal route calculation and traffic flow.