Configuring DHCP

The client-side configuration of DHCP is simple. It usually only involves enabling the DHCP option (see Screen A).

The server-side configuration is somewhat more involved. First you install the DHCP software by accessing the Network icon on the Control Panel to get to the TCP/IP configuration information. Select the DHCP Server Service option located in the TCP/IP Installation Options dialog to install the software. Server support is available in both the Windows NT Workstation and Windows NT Server environments, but a single system can only be either a DHCP server or a DHCP client, not both.

When the software is loaded, you can configure the DHCP server through the DHCP Manager program in the Network Administration group. The initial display shows the available DHCP servers--you will see only your local system. Select the local system, access the Scope menu, and choose Create to access the Create Scope configuration window (see Screen B).

In the Create Scope window, configure the following entries:

  1. IP Address Pool (Start Address, End Address, and Subnet Mask): These three fields are the basic components of a scope. The start and end addresses define the range of addresses included and the subnet mask defines which IP address bits are relevant for the network covered by that scope (the subnet mask is logically XORed with IP addresses to determine the relevant address bits).
  2. Exclusion Range (Start Address and End Address): This is where you specify individual addresses or ranges of addresses to be excluded from the IP address pool. This allows you to include non-DHCP systems in a logical group (the same scope) with DHCP systems.
  3. Lease Duration: These entries control how long each system can "own" an IP address. When the lease duration expires, the system is assigned a new IP address. The lease renewal process allows DHCP to detect and recover unused addresses.
  4. Name: This is the logical name for this scope.
  5. Comment: This is an optional field for your comments.

When the information is complete, click on OK. If you want the scope activated (i.e., if you aren't going to enable other DHCP options, such as configuring matching WINS or DNS servers), click on Yes. Otherwise, you can configure additional DHCP options and activate the scope later via the Activate option on the Scope menu.