200-301 Question 356
Select 3A network engineer has configured a DHCP server on a router to dynamically assign IP addresses to client devices in a subnet. However, some devices are reporting IP address conflicts. Upon investigation, the engineer notices that there is another DHCP server active on the same subnet. Which of the following steps can the engineer take to resolve this issue?
- A
Disable the DHCP service on the unauthorized DHCP server.
- B
Configure DHCP Snooping on the network switches.
- C
Increase the lease time of IP addresses on the DHCP server.
- D
Assign static IP addresses to all devices in the subnet.
- E
Use IP helper addresses to direct DHCP requests to the correct server.
Show answer and explanation
Correct answers: A, B, E
Explanation
IP address conflicts can occur when multiple DHCP servers are active on the same subnet and assign overlapping IP addresses. Disabling the unauthorized DHCP server or implementing DHCP Snooping on switches can prevent the unauthorized server from assigning IP addresses. Additionally, IP helper addresses can direct DHCP requests to the correct server, ensuring consistent and conflict-free IP assignments.
- A. Correct.
Disabling the DHCP service on the unauthorized DHCP server will stop it from assigning conflicting IP addresses, resolving the conflict at its source.
- B. Correct.
Configuring DHCP Snooping on the switches ensures that only trusted DHCP servers are allowed to provide IP address information, preventing unauthorized DHCP servers from causing conflicts.
- C. Incorrect.
Increasing the lease time does not address the root cause of the issue (multiple DHCP servers) and will not prevent IP conflicts.
- D. Incorrect.
Assigning static IP addresses to all devices is a time-consuming and impractical solution for large networks, and it does not address the underlying issue of unauthorized DHCP servers.
- E. Correct.
Using IP helper addresses can ensure that DHCP requests are forwarded to the authorized DHCP server, helping to prevent conflicts caused by multiple DHCP servers.