From Wikipedia, the free encyclopedia
Original author(s)Ted Lemon
Developer(s)Internet Systems Consortium
Initial release1999; 25 years ago (1999)
Stable release
4.4.3-P1 / October, 2022[1]
Written inC
Operating systemBSD, Linux, Solaris
TypeDHCP server
LicenseISC License, MPL2.0
As of5 2023

dhcpd (an abbreviation for "DHCP daemon") was a DHCP server program that operates as a daemon on a server to provide Dynamic Host Configuration Protocol (DHCP) service to a network.[3] This implementation, also known as ISC DHCP, is one of the first and best known, but there are now a number of other DHCP server software implementations available.

Clients may solicit an IP address from a DHCP server when they need one. The DHCP server then offers the "lease" of an IP address to the client, which the client is free to request or ignore. If the client requests it and the server acknowledges it, then the client is permitted to use that IP address for the "lease time" specified by the server. At some point before the lease expires, the client must re-request the same IP address if it wishes to continue to use it.[4]

Issued IP addresses are tracked by dhcpd through a record in the dhcpd.leases file.[5] This allows the server to maintain state over restarts of the dhcp service, which could otherwise lead to duplicate IP addresses being issued when server issued the same IP address again while another client still has the right to use it.[3]

This reference implementation of DHCP is developed by the Internet Systems Consortium[6] and is supported on Linux, Mac OS X, FreeBSD, and Solaris.[7]

Remote access to a running instance of dhcpd is provided by the Object Management Application Programming Interface (OMAPI).[8][9] This API allows manipulation of the internal state of a running instance of the dhcpd server or client. On the server side, this interface allows editing of registration information for managed nodes. Uses on the client include fetching configuration information, releasing and renewing leases, and changing which interfaces are managed by the DHCP client.

ISC DHCP was declared End-of-Life in October, 2022.[10] ISC is developing a new DHCP software system, which is intended to eventually replace it.[11] This software, Kea, includes a DHCP server only (so, no client or relay yet) and is supported on the same platforms as ISC DHCP. It is distributed under the Mozilla Public License (MPL2.0).[12]

ISC DHCP adopted the Mozilla Public License (MPL2.0) with the release of 4.4.1.[13]

See also[edit]


  1. ^ "Downloads".
  2. ^ "Isc Dhcp News". Lists.isc.org. 9 April 2019. Retrieved 2022-08-06.
  3. ^ a b Lemon, Ted (2012). "dhcpd – Dynamic Host Configuration Protocol Server". Internet Systems Consortium. Retrieved January 22, 2020.
  4. ^ Droms, Ralph (March 1997). "RFC 2131 – Dynamic Host Configuration Protocol". Network Working Group. Internet Engineering Task Force. doi:10.17487/RFC2131.
  5. ^ Lemon, Ted (2018). "dhcpd.leases – DHCP Client Lease File". Internet Systems Consortium. Archived from the original on April 6, 2018. Retrieved April 5, 2018.
  6. ^ "DHCP – Internet Systems Consortium". Internet Systems Consortium. 2018. Retrieved April 5, 2018.
  7. ^ "README" (PDF). Internet Systems Consortium. 2012. Archived from the original (PDF) on 4 July 2012. Retrieved 14 June 2012.
  8. ^ "ISC DHCP API Interface". IPAM. Retrieved 25 January 2013.
  9. ^ Ralph Droms and Ted Lemon (2003). The DHCP handbook. Sams. pp. 239, 316. ISBN 9780672323270.
  10. ^ Consortium, Internet Systems (2022-10-04). "ISC DHCP Server has reached EOL". www.isc.org. Retrieved 2023-04-06.
  11. ^ "MOSS supports four more open source projects in Q3 2016 with $300k". Mozilla Foundation. October 3, 2016. Retrieved 3 November 2016.
  12. ^ "Kea wiki page". Kea.isc.org. Internet Systems Consortium. Retrieved 3 November 2016.
  13. ^ "DHCP 4.4.0 announcement". isc.org. Internet Systems Consortium. 9 January 2018. Retrieved 5 April 2018.

External links[edit]