ICND2: Interconnecting Cisco Networking Devices Part 2 (legacy) — Question 147

While troubleshooting the failure of an OSPFv3 Ethernet connection between routers R1 and R2, you determine that the hello timers are mismatched and that R2 is configured with default settings.
Which command do you enter on R1 to correct the problem?

Answer options

• A. R1(config-if)#ipv6 ospf hello-interval 20
• B. R1(config-if)#ip ospf hello-interval 10
• C. R1(config-if)#ip ospf hello-interval 20
• D. R1(config-if)#no ipv6 ospf hello-interval

Correct answer: B

Explanation

The correct command is B, which sets the hello interval to 10 seconds on R1, matching the default OSPFv3 hello timer settings. Option A is incorrect because it uses the IPv6 OSPF command instead of the OSPF command for IPv4. Option C sets the interval to 20 seconds, which does not resolve the mismatch. Option D incorrectly attempts to disable the IPv6 hello interval, which is not relevant to the problem.