Which OSPF network type must be statically configured for DR/BDR election to occur?
- broadcast
- point-to-point
- point-to-multipoint
- loopback
- nonbroadcast
Explanation: The nonbroadcast network type is used on multiaccess networks that interconnect more than two routers but lack inherent broadcast or multicast capabilities, such as Frame Relay or ATM. Because the network cannot flood OSPF Hello packets to discover peers, neighbors must be statically configured by the administrator. Once these manual neighbor relationships are defined, OSPF proceeds to perform a DR/BDR election to optimize the exchange of routing information and manage link-state synchronization on the segment.
Other network types behave differently:
- Broadcast: Also performs a DR/BDR election, but it uses multicast to discover neighbors dynamically rather than requiring static configuration.
- Point-to-point: Uses multicast for dynamic discovery but has no DR/BDR election because only two routers can exist on the segment.
- Point-to-multipoint: Discovers neighbors dynamically using multicast and has no DR/BDR election.
- Loopback: Is the default for loopback interfaces and does not involve DR/BDR elections.
Related exam: Modules 8 – 13: Checkpoint Exam: Network Routing Answers (CCNP ENCOR v9)
