CCNA: Cisco Certified Network Associate — Question 425

OSPF must be configured between routers R1 and R2. Which OSPF configuration must be applied to router R1 to avoid a DR'BDR election?

Answer options

• A. router ospf 1 network 192.168.1.1 0.0.0.0 area 0 interface e1/1 ip address 192.168.1.1 255.255.255.252 ip ospf cost 0
• B. router ospf 1 network 192.168.1.1 0.0.0.0 area 0 hello interval 15 interface e1/1 ip address 192.168.1.1 255.255.255.252
• C. router ospf 1 network 192.168.1.1 0.0.0.0 area 0 interface e1/1 ip address 192.168.1.1 255.255.255.252 ip ospf network broadcast
• D. router ospf 1 network 192.168.1.1 0.0.0.0 area 0 interface e1/1 ip address 192.168.1.1 255.255.255.252 ip ospf network point-to-point

Correct answer: D

Explanation

The correct answer is D, which configures the interface as point-to-point, thus eliminating the need for DR/BDR elections. Option A incorrectly sets the OSPF cost but does not affect election behavior, while option B modifies the hello interval, which does not prevent election. Option C sets the network type to broadcast, which allows for DR/BDR elections to occur.