When planning a DHCP network, how do you determine the number of servers that should be used?

Answer 1

This actually depends on serval issues. Like subnet etc.
Here is a link to help explain it

http://www.comptechdoc.org/os/linux/manual4/networkprefix.html

Answer 2

You should only have 1 active DHCP server in any network. If your network is extremely large you can break up your DHCP between servers, just make sure they don't share the same scopes.

Answer 3

Planning DHCP networks
This topic covers the following DHCP network planning issues.

• How to determine the number of DHCP servers to use

• How to support DHCP clients on additional subnets

• Planning for routed DHCP networks

• Other planning considerations for enterprise networks


How to determine the number of DHCP servers to use
Because there is no fixed limit to the maximum number of clients a DHCP server can service or to the number of scopes you can create on a DHCP server, the primary factors to consider when you determine the number of DHCP servers to use are network architecture and server hardware. For example, in a single subnet environment, only one DHCP server is necessary, although you may want to use two servers or deploy a DHCP server cluster for increased fault tolerance. In multiple subnet environments, routers must forward DHCP messages between subnets, so router performance can affect your DHCP service. In both cases, DHCP server hardware affects service to clients.

When you determine the number of DHCP servers to use, consider the following:

• The location of routers on the network and whether you want a DHCP server on each subnet.

When you extend the use of a DHCP server across more than one network, you often need to configure additional DHCP relay agents and, in some cases, use superscopes as well.

• The transmission speed between the segments for which DHCP service is provided.

If you have slower WAN links or dial-up links, you may need a DHCP server on both sides of these links to service clients locally.

• The speed of the server disk drives and the amount of random access memory (RAM) installed in the DHCP server computer.

In order to maximize DHCP server performance, use the fastest disk drives and the most RAM possible. Carefully evaluate disk access time and average times for disk read and write operations when you plan for your DHCP server hardware needs.

• Practical constraints based on the IP address class selected for use and other server configuration details.


You can test your DHCP servers before deployment on the organization network in order to determine the limitations and abilities of your hardware and to see whether network architecture, traffic, and other factors affect DHCP server performance. Hardware and configuration tests also allow you to determine the number of scopes to configure at each server.

To provide a general idea of DHCP server performance, a DHCP server running Microsoft® Windows Server 2003 was run in a test lab environment, and a custom stress application was used against the server. The details of this lab test can help you configure your tests and determine how many DHCP servers to use on your network: