200-301 Question 380
Select 3A network administrator is configuring a router to act as a DHCP relay to provide IP addresses to devices in a remote subnet. The DHCP server is located in another subnet. After configuration, the devices in the remote subnet are still not receiving IP addresses. Which of the following steps should the administrator take to resolve the issue?
- A
Verify that the 'ip helper-address' command is correctly configured on the router interface connected to the remote subnet.
- B
Ensure the DHCP server is reachable from the router by verifying connectivity using the 'ping' command.
- C
Enable the 'service dhcp' command on the router acting as a relay.
- D
Check if the router has a static route to the DHCP server's network in its routing table.
- E
Enable NAT (Network Address Translation) on the router to translate DHCP requests from the remote subnet.
Show answer and explanation
Correct answers: A, B, D
Explanation
To ensure proper DHCP relay functionality, the router must be configured with the 'ip helper-address' command to forward DHCP requests. Additionally, the DHCP server must be reachable from the relay, and the router must have a valid route to the DHCP server's network. The 'service dhcp' command and NAT are not relevant in this scenario as the router is acting as a relay, not as a DHCP server or NAT device.
- A. Correct.
The 'ip helper-address' command is essential to configure the router as a DHCP relay. Without it, the router will not forward DHCP requests to the server.
- B. Correct.
If the DHCP server is not reachable, the DHCP relay cannot forward requests to it. Verifying connectivity helps isolate potential network issues.
- C. Incorrect.
The 'service dhcp' command is only required when the router is acting as a DHCP server, not as a relay.
- D. Correct.
The router needs to know how to reach the DHCP server's network. A missing or incorrect static route can prevent communication between the relay and the server.
- E. Incorrect.
NAT is not required for DHCP relay functionality and would not resolve the issue described in this scenario.