Determining DHCP Server Locations
Updated: March 28, 2003
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
To determine where to locate your DHCP servers, consider whether you are deploying a distributed, centralized, or combined DHCP infrastructure.
For a distributed DHCP infrastructure, locate a DHCP server on each subnet. Because distributed infrastructures use a DHCP server on each subnet, they require a greater number of servers than centralized networks. For example, a network that includes 30 subnets and that is using a true distributed topology requires at least 30 DHCP servers, and possibly more to provide for redundancy.
In a centralized DHCP infrastructure, DHCP servers are placed in a central location. A centralized DHCP topology requires the deployment of DHCP/bootstrap protocol (BOOTP) relay agents. Additional hardware resources are not generally required for DHCP relay agents; in most cases, the routers that are positioned between each subnet can assume this role, as defined in RFC 1542. If the routers cannot relay DHCP messages, configure a computer running Windows Server 2003 to act as a DHCP/BOOTP relay agent. For more information about configuring relay agents, see "Enabling DHCP Support for Multiple Subnets" later in this chapter.
Combining both distributed and centralized DHCP infrastructures provides the maximum efficiency for your network. In a combined DHCP infrastructure, the locations for DHCP servers are based on the physical characteristics of the local area network (LAN) or wide area network (WAN) infrastructure, and not the logical groupings defined by the Active Directory logical structure. DHCP servers are not required for every subnet if the connecting routers support DHCP/BOOTP relay agents. You can administer Windows Server 2003 DHCP servers remotely from a computer running Windows Server 2003 and Microsoft Management Console (MMC) DHCP snap-in. You can also administer a DHCP server remotely at the command line by using Netsh commands for DHCP, or you can remotely administer a DHCP server from a computer running Microsoft® Windows® XP Professional that has the Windows Server 2003 Administration Tools Pack installed. You must have the correct level of security permissions in order to administer a DHCP server. For more information about using the Windows Server 2003 Administration Tools Pack, see "Windows Server 2003 Administration Tools PackWindows Server 2003 Administration Tools Pack" in Help and Support Center for Windows Server 2003.