200-301 Question 339
Single answerA network engineer is configuring a point-to-point link between two routers using a serial connection. The engineer notices that the link is not coming up, and the 'show ip interface brief' command indicates the interface is administratively down. What is the first action the engineer should take to resolve this issue?
- A
Verify the IP address configuration on both ends of the link.
- B
Enable the interface using the 'no shutdown' command.
- C
Check the encapsulation type configured on the interface.
- D
Replace the serial cable to eliminate hardware issues.
Show answer and explanation
Correct answer: B
Explanation
When an interface is administratively down, it means it has been manually disabled. The 'no shutdown' command is required to bring the interface up before addressing other potential configuration or hardware issues.
- A. Incorrect.
Verifying the IP address configuration is important, but if the interface is administratively down, the IP settings are irrelevant until the interface is enabled.
- B. Correct.
If the interface is administratively down, the 'no shutdown' command must be issued to enable it before any further troubleshooting.
- C. Incorrect.
Checking the encapsulation type is relevant for layer 2 issues, but it will not help if the interface is administratively down.
- D. Incorrect.
Replacing the serial cable may be necessary for physical issues, but it is not the first step to resolve an administratively down state.