- DHCP (Dynamic Host Configuration Protocol) is
a communications protocol that lets network
administrators centrally manage and automate the
assignment of Internet Protocol (IP) addresses
in an organization's network. Using the Internet
Protocol, each machine that can connect to the
Internet needs a unique IP address, which is
assigned when an Internet connection is created
for a specific computer. Without DHCP, the IP
address must be entered manually at each
computer in an organization and a new IP address
must be entered each time a computer moves to a
new location on the network. 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
plugged into a different place in the network.
DHCP uses the concept of a "lease" or amount
of time that a given IP address will be valid
for a computer. The lease time can vary
depending on how long a user is likely to
require the Internet connection at a particular
location. It's especially useful in education
and other environments where users change
frequently. Using very short leases, DHCP can
dynamically reconfigure networks in which there
are more computers than there are available IP
addresses. The protocol also supports static
addresses for computers that need a permanent IP
address, such as Web servers.
DHCP is an extension of an earlier network IP
management protocol, Bootstrap Protocol (BOOTP).
DHCP is a more advanced protocol, but both
configuration management protocols are commonly
used and DHCP can handle BOOTP client requests.
Some organizations use both protocols, but
understanding how and when to use them in the
same organization is important. Some operating
systems, including Windows NT/2000, come with
DHCP servers. A DHCP or BOOTP client is a
program that is located in (and perhaps
downloaded to) each computer so that it can be
configured. |
