200-301 Question 345
Single answerA network engineer is configuring OSPF on a router. The router has three active interfaces with the following IP addresses and subnet masks: 192.168.1.1/24, 10.0.0.1/24, and 172.16.0.1/16. The engineer has not manually set a router ID. What will the router ID be after OSPF starts?
- A
192.168.1.1
- B
10.0.0.1
- C
172.16.0.1
- D
The router will not have a router ID and OSPF will fail to start
Show answer and explanation
Correct answer: A
Explanation
In OSPF, if the router ID is not manually configured, the router will automatically select the highest IP address from the active interfaces as the router ID. In this scenario, the highest IP address is 192.168.1.1, so it will be chosen as the router ID.
- A. Correct.
This is the correct answer because OSPF automatically selects the highest IP address from the active interfaces as the router ID when no manual configuration is provided.
- B. Incorrect.
This is not correct because 10.0.0.1 is not the highest IP address among the active interfaces.
- C. Incorrect.
This is not correct because 172.16.0.1 is not the highest IP address among the active interfaces.
- D. Incorrect.
This is not correct because OSPF will automatically assign a router ID if no manual configuration is provided and there are active interfaces.