200-301 Question 379
Single answerA network administrator has configured a router to act as a DHCP relay agent to forward DHCP requests from a remote subnet (192.168.10.0/24) to a central DHCP server located at 192.168.1.100. However, devices on the remote subnet are not receiving IP addresses. Which configuration step is most likely missing?
- A
The 'ip helper-address 192.168.1.100' command on the router interface facing the remote subnet
- B
The configuration of a default route to the DHCP server on the router
- C
The configuration of the DHCP pool for the remote subnet on the router
- D
The activation of the 'service dhcp' command on the router
Show answer and explanation
Correct answer: A
Explanation
To configure a router as a DHCP relay agent, the 'ip helper-address' command must be applied to the interface connected to the subnet where DHCP requests originate. This command specifies the IP address of the DHCP server to which requests should be forwarded. Without this configuration, the router will not know where to send the DHCP requests, resulting in devices on the remote subnet failing to obtain IP addresses.
- A. Correct.
The 'ip helper-address' command is necessary to enable the router to forward DHCP requests from the remote subnet to the DHCP server. Without this command, the router will not relay the requests.
- B. Incorrect.
While a default route will ensure that the router can reach the DHCP server, it is not sufficient on its own to enable DHCP relay functionality.
- C. Incorrect.
Configuring a DHCP pool is only required if the router itself is acting as a DHCP server, not as a DHCP relay agent.
- D. Incorrect.
The 'service dhcp' command is used to enable the DHCP server functionality on the router, but it is not required for DHCP relay operation.