DHCP servers

  • Article

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

DHCP servers

Configuring DHCP servers for a network provides the following benefits:

  • The administrator can assign and specify global and subnet-specific TCP/IP parameters centrally for use throughout the entire network.

  • Client computers do not require manual TCP/IP configuration.

  • When a client computer moves between subnets, its old IP address is freed for reuse. The client reconfigures its TCP/IP settings automatically when the computer is restarted in its new location.

  • Most routers can forward DHCP and BOOTP configuration requests, so DHCP servers are not required on every subnet in the network.

How clients use servers

A computer running Windows XP becomes a DHCP client if Obtain an IP address automatically is selected in its TCP/IP properties. When a client computer is set to use DHCP, it accepts a lease offer and can receive from the server the following:

  • Temporary use of an IP address known to be valid for the network it is joining.

  • Additional TCP/IP configuration parameters for the client to use in the form of options data.

Also, if conflict detection is configured, the DHCP server attempts to ping each available address it intends to offer prior to presenting the address in a lease offer to a client. This ensures that each IP address offered to clients is not already in use by another non-DHCP computer that uses manual TCP/IP configuration.

How servers provide optional data

In addition to an IP address, DHCP servers can be configured to provide optional data to fully configure TCP/IP for clients. Some of the most common DHCP option types configured and distributed by the DHCP server during leases include:

  • Default gateways (routers), which are used to connect a network segment to other network segments.

  • Other optional configuration parameters to assign to DHCP clients, such as IP addresses for the DNS servers or WINS servers that the client can use in resolving network host names.

For more information, see DHCP options.