Applies To: Windows Server 2008
The network architecture and server hardware are the primary considerations when determining the number of DHCP servers in your design, because each DHCP server can theoretically support an unlimited number of clients. For example, in a single subnet environment, only one DHCP server is necessary, although you might want to use two servers or deploy a DHCP server cluster for increased fault tolerance. In an environment with multiple subnets, router performance can affect the DHCP service because DHCP messages must be forwarded across subnets. Therefore, scaling the DHCP service involves network infrastructure issues for most enterprise environments.
You can create an unlimited number of scopes on a DHCP server. However, a DHCP server should ideally host no more than 1,000 scopes. When adding a large number of scopes to the server, be aware that each scope creates a corresponding need for additional disk space for the DHCP server registry and the server paging file.
Before deployment, you should test your DHCP servers on the network to determine the limitations and abilities of your hardware and to see whether the network architecture, traffic, and other factors affect DHCP server performance.