This article provides some basic information about Dynamic Host Configuration Protocol (DHCP) and how it relates to the AirPort Base Station.

DHCP (Dynamic Host Configuration Protocol) is a protocol that lets network administrators centrally manage and automate the assignment of Internet Protocol (IP) addresses. Its purpose is to enable individual computers on an IP network to extract their configurations from the DHCP server or servers, in particular, servers that have no exact information about the individual computers until they request the information. This can be used in a LAN environment or by an ISP.

The ability to do this reduces the work necessary to administer a large IP network. Without DHCP, the IP address must be entered manually at each computer and, if computers move to another location in another part of the network, a new IP address must be entered. DHCP lets a network administrator supervise and distribute IP addresses from a central point and automatically sends a new IP address when a computer is connected in a different place in the network, or reconnects to an ISP.

Note: The following definitions will be helpful when setting up the AirPort Base Station for use with your Internet Service Provider:

What is an IP address?

An IP address (also called an IP number) is a number (typically written as four numbers separated by periods, i.e. 107.4.1.3 or 84.2.1.111) which uniquely identifies a computer that is making use of the Internet. It is analogous to your telephone number in that the telephone number is used by the telephone network to direct calls to you. The IP address is used by the Internet to direct data to your computer, e.g. the data your web browser retrieves and displays when you surf the net. One task of DHCP is to assist in the problem of getting a functional and unique IP number into the hands of the computers that make use of the Internet.

What is a MAC address?

A MAC address (also called an Ethernet address or an IEEE MAC address) is a number (typically written as twelve hexadecimal digits, 0 through 9 and A through F, or as six hexadecimal numbers separated by periods or colons, i.e. 0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an Ethernet interface. Unlike the IP number, it includes no indication of where your computer is physically located. In DHCP's typical use, the server uses a requesting computer's MAC address to uniquely identify it.

What is a DHCP lease?

A DHCP lease is the amount of time that the DHCP server grants to the DHCP client permission to use a particular IP address. A typical server allows its administrator to set the lease time.

Note: This article provides information which did not originate at Apple Computer, Inc., and Apple Computer is not responsible for its content. This information is provided for your information.

A comprehensive DHCP document can be found at:

http://www.cs.yale.edu/CF/HI/ZooHelp/dhcp.faq.html