Where to place your DHCP Server in your organization's netwkork infrastructure

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".

• 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.