What is DHCP?

Dynamic Host Configuration Protocol (DHCP) is a network management protocol used to automatically assign IP addresses, subnet masks, DNS servers, and other network configurations to devices. Instead of manually entering this information for each device, DHCP takes care of it for all devices on the network, streamlining network administration.

What You Will Need

  1. Two domain-connected Windows servers (I’m using Windows Server 2022, but you can use any supported version).
  2. The DHCP server role installed on each server.

What to Do

  1. Set Up a Scope on the Primary DHCP Server:

    • Open Server Manager, go to the “Tools” tab, and select “DHCP.”
    • Right-click on “IPv4” and choose “New Scope.” Name the scope and click “Next.”
    • For a test environment, you can use an IP range like 192.168.0.2 to 192.168.0.224 with a subnet mask of 255.255.255.0 (giving you 254 usable IP addresses).
    • If you need to exclude specific IP addresses (e.g., for devices requiring static IPs), you can specify them in the next screen. Otherwise, skip this step.
    • Set the DHCP lease duration. The default values are typically fine.
    • In the “Default Gateway” field, enter 192.168.0.1.

  2. Configure Failover:

    • Right-click on “IPv4” and select “Configure Failover.”
    • Choose the scope you want to include in the failover setup.
    • Click “Add Server,” then “Browse” to locate your second server by typing in its hostname.
    • Click “Next” to set up the failover relationship. Select “Load Balance” as the mode, and enter a password for the failover configuration.
    • Complete the setup.

Why You Want a Failover

Setting up a DHCP failover ensures network reliability and continuous availability of IP addresses and configurations. If the primary DHCP server fails, the secondary server takes over seamlessly, preventing disruptions in connectivity. This failover mechanism helps maintain business operations smoothly and enhances network stability.