DHCP
| Application layer | FTP | SMTP | HTTP | IRC | ... |
| Transport layer | TCP | UDP | SCTP | ICMP | ... |
| Network layer | IP | IPv6 | ARP | DHCP | ... |
| Data link layer | Ethernet | Token ring | FDDI | 802.11 WiFi | ... |
Dynamic Host Configuration Protocol (DHCP), a networking protocol, provides a means to allocate IP addresses dynamically to computers on a local area network (LAN). A network administrator assigns a range of IP addresses to DHCP and each client computer on the LAN has its TCP/IP software configured to request an IP address automatically from the DHCP server when that client computer starts up. The request-and-grant process uses a lease concept with a controllable time period. This eases the network installation procedure on the client computer side considerably.
In addition to the IP address, a DHCP server can provide other information like DNS server addresses, a DNS domain or a gateway IP address.
DHCP appeared as a standard protocol in October 1993. RFC 2131 (http://www.faqs.org/rfcs/rfc2131.html) provides the latest (March 1997) DHCP definition.
Microsoft introduced DHCP on their NT server with Windows NT version 3.5 in late 1994. In addition to most server operating systems, many devices, like Ethernet routers and DSL routers, provide some sort of DHCP server.
See also: RARP, BOOTP, Zeroconf

