ISC DHCP Implementation

The Internet Systems Consortium (ISC) publishes a freely downloadable DHCP server. If you would like to contribute to ISC to assist them in continuing to make quality open source software, please visit their donations page at This section summarizes the configuration of ISC DHCP server for your convenience.

The ISC provides documentation and tips documents on their website and also offers support contracts for technical assistance and support. The ISC DHCP server can be installed on a variety of platforms including FreeBSD, OpenBSD, BSD/OS, Digital Tru64 Unix, Solaris, Linux systems using a 2.4 kernel, as well as on HP-UX and AIX systems with a single network interface. It does not run on Microsoft Windows as of DHCPD version 4.1. Please consult the readme file with your distribution for installation details for your platform.

The configuration of the DHCP server is defined by setting parameters within the dhcpd.conf file on the server. When the DHCP service starts it reads this configuration file to initialize the dhcpd service. The configuration file, stored as an ASCII text file, defines server level policy settings, subnets, address pools, options, client classes and host or manual DHCP declarations. Statements within the configuration file are classified as either declarations or parameters. Declarations define network topology and associated addresses and clients, while parameters define value settings for configuring clients and for governing server behavior.