200-301 Question 406
Single answerA network engineer is troubleshooting a connectivity issue in a branch office. The branch office router is configured with a default route to the ISP's router. The engineer runs a traceroute to a public IP address, but it shows that the packet is not leaving the branch office network. Which routing technique should the engineer verify to resolve the issue?
- A
Ensure the branch office router has a static route to the ISP's network
- B
Verify that the default route on the branch office router is correct
- C
Enable NAT (Network Address Translation) on the branch office router
- D
Check if the public IP address is reachable from the ISP's router
Show answer and explanation
Correct answer: B
Explanation
The engineer needs to verify that the default route on the branch office router is correct. A default route is used to forward packets destined for unknown networks, such as the internet, to the next-hop router (in this case, the ISP's router). If the default route is misconfigured or missing, the packet will not leave the branch office network.
- A. Incorrect.
A static route to the ISP's network is unnecessary since a default route is already configured. The default route should suffice for this purpose.
- B. Correct.
The default route is critical for directing traffic destined for unknown networks toward the ISP. If the default route is misconfigured, the packet will not leave the branch office network.
- C. Incorrect.
While NAT is necessary for translating private IP addresses to public ones, it does not affect whether the default route is correctly configured.
- D. Incorrect.
Checking if the public IP address is reachable from the ISP's router is a step beyond the branch office's control and does not directly address the immediate issue.