Dynamic Host Configuration Protocol

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Dynamic Host Configuration Protocol, is a client-server technology for dynamically assigning IP addresses to devices on a network.[1]

This gets rid of the need to statically give an IP to a device by an administrator. Thus, a device can have a different IP address every time it connects to the network automatically. Even if the device addresses do not change frequently, such as on servers, DHCP makes the job of the administrator much easier whenever it is necessary to change addresses. It may be necessary to renumber if the organization that has a particular address range merges with, or is acquired by, a larger organization, and the new owners want to make the addresses consistent.

It frees the network administrator from the hassle of having to know all the IP addresses on his network and giving valid IP address to each new device that connects to it.[2] A very effective way to keep track of real devices, rather than changing IP addresses, is to have the DHCP server automatically pass assignments to a Domain Name System (DNS) server.[3] A host name such as Desk2-Room102.Campus3.example.com can be very helpful in troubleshooting when you can ask the DNS server what number has been assigned to it. Many commercial ISPs use this technology.

It is also used on more complex networks where the connected devices continually change their IP address while still connected.

General issues

  • Host configuration/unique host naming
  • Lease time considerations

IPv4 issues and support mechanisms

  • Proxies for PPP/IPCP
  • Collision avoidance
  • DHCP failover mechanisms

IPv6 issues and support mechanisms

Internet Protocol version 6 has a DHCP version, also called stateful address assignment. It also has a self-configuring alternative called stateless autoconfigurtion


  1. R. Droms (March 1997), Dynamic Host Configuration Protocol, RFC2131
  2. P. Ferguson, H. Berkowitz (January 1997), Network Renumbering Overview: Why would I want it and what is it anyway?, RFC2071
  3. B. Wellington (November 2002), Secure Domain Name System (DNS) Dynamic Update, RFC3007