300-440 Question 242
Select 4A network engineer is tasked with configuring a DHCP server on a Cisco router to serve IP addresses for a new VLAN in the network. The VLAN has a subnet of 192.168.50.0/24, and the default gateway for devices in this VLAN should be 192.168.50.1. Which of the following steps must the engineer take to ensure proper DHCP functionality?
- A
Define a DHCP pool with the 'ip dhcp pool' command and specify the network range.
- B
Configure the 'default-router' option within the DHCP pool to set the default gateway as 192.168.50.1.
- C
Enable the 'service dhcp' command on the router to activate the DHCP service.
- D
Set up a helper address using the 'ip helper-address' command on the router interface connected to the VLAN.
- E
Exclude the default gateway IP address using the 'ip dhcp excluded-address' command.
Show answer and explanation
Correct answers: A, B, C, E
Explanation
To configure a DHCP server on a Cisco router, the engineer must create a DHCP pool and specify the network range, define the default gateway using the 'default-router' option, enable the DHCP service with the 'service dhcp' command, and exclude the IP address of the default gateway to prevent IP conflicts. The 'ip helper-address' command is unnecessary because the router is the local DHCP server.
- A. Correct.
This is correct. The 'ip dhcp pool' command allows the creation of a DHCP pool, and specifying the network range ensures the DHCP server assigns IP addresses within the correct subnet.
- B. Correct.
This is correct. The 'default-router' option is necessary to define the default gateway for devices in the VLAN, which ensures proper routing for connected devices.
- C. Correct.
This is correct. The 'service dhcp' command is required to enable the DHCP service on the router and ensure it functions properly.
- D. Incorrect.
This is incorrect. The 'ip helper-address' command is used to forward DHCP requests to an external DHCP server, which is not needed here because the DHCP server is configured locally on the router.
- E. Correct.
This is correct. The 'ip dhcp excluded-address' command ensures that the router does not assign the default gateway IP address (192.168.50.1) to other devices in the VLAN.