Two OSPF neighbors are stuck in the EXCHANGE/EXSTART state. What could be the reason for this?
- An OSPF interface is passive on one router.
- Multicast is broken on the link that connects the two routers.
- There is an MTU issue.
- An access list is blocking OSPF hellos on the interface.
Explanation: If OSPF neighbors are stuck in the EXSTART/EXCHANGE state, it is most commonly caused by an MTU mismatch on the connecting link. This prevents the routers from successfully exchanging Database Description (DBD) packets, which is required to progress to the Loading and Full states.
Related exam: Checkpoint Exam: Layer 3 Technologies – OSPF
