What indicates to a link-state router that a neighbor is unreachable?
- if the router no longer receives hello packets
- if the router receives an update with a hop count of 16
- if the router receives an LSP with previously learned information
- if the router no longer receives routing updates
Explanation: OSPF routers send hello packets to monitor the state of a neighbor. When a router stops receiving hello packets from a neighbor, that neighbor is considered unreachable and the adjacency is broken.
More Questions: Modules 1 – 2: OSPF Concepts and Configuration Exam Answers