Product SiteDocumentation Site

Chapter 21. Dynamic Host Configuration Protocol (DHCP)

21.1. Why Use DHCP?
21.2. Configuring a DHCP Server
21.2.1. Configuration File
21.2.2. Lease Database
21.2.3. Starting and Stopping the Server
21.2.4. DHCP Relay Agent
21.3. Configuring a DHCP Client
21.4. Configuring a Multihomed DHCP Server
21.4.1. Host Configuration
21.5. Additional Resources
21.5.1. Installed Documentation
Dynamic Host Configuration Protocol (DHCP) is a network protocol that automatically assigns TCP/IP information to client machines. Each DHCP client connects to the centrally located DHCP server, which returns that client's network configuration (including the IP address, gateway, and DNS servers).

21.1. Why Use DHCP?

DHCP is useful for automatic configuration of client network interfaces. When configuring the client system, the administrator chooses DHCP instead of specifying an IP address, netmask, gateway, or DNS servers. The client retrieves this information from the DHCP server. DHCP is also useful if an administrator wants to change the IP addresses of a large number of systems. Instead of reconfiguring all the systems, he can just edit one DHCP configuration file on the server for the new set of IP addresses. If the DNS servers for an organization changes, the changes are made on the DHCP server, not on the DHCP clients. When the administrator restarts the network or reboots the clients, the changes will go into effect.
If an organization has a functional DHCP server properly connected to a network, laptops and other mobile computer users can move these devices from office to office.