APIPA – Automatic Private IP Addressing

APIPA is short for Automatic Private IP Addressing, a feature of Windows operating systems, meant for non-routed small business environments, usually less than 25 clients.

With APIPA, DHCP clients can automatically self-configure an IP address and subnet mask when a DHCP server isn’t available. When a DHCP client boots up, it first looks for a DHCP server in order to obtain an IP address and subnet mask.

Automatic Configurations and Service Checks

If the client is unable to find the information, it uses APIPA to automatically configure itself with an IP address. The IP address range is 169.254.0.1 through 169.254.255.254. The client also configures itself with a default class B subnet mask of 255.255.0.0. A client uses the self-configured IP address until a DHCP server becomes available.

The APIPA service also checks regularly for the presence of a DHCP server (every five minutes, according to Microsoft). If it detects a DHCP server on the network, APIPA stops, and the DHCP server replaces the APIPA networking addresses with dynamically assigned addresses.

Vangie Beal
Vangie Beal
Vangie Beal is a freelance business and technology writer covering Internet technologies and online business since the late '90s.

Related Articles

@ Sign

Pronounced at sign or simply as at, this symbol is used in e-mail addressing to separate the user' name from the user's domain name,...

Munging

(MUHN-jing) Munging (address munging), is the act of altering an email address posted on a Web page to make it unreadable to bots and...

How to Create an RSS Feed

In the second installment of RSS how-to, we look at some of the nonrequired (optional) channel and item tags, discuss RSS specifications in-depth and...

Dictionary Attack

(n.) (1) A method used to break security systems, specifically password-based security systems, in which the attacker systematically tests all possible passwords beginning with...

ScalaHosting

ScalaHosting is a leading managed hosting provider that offers secure, scalable, and affordable...

HRIS

Human resources information system (HRIS) solutions help businesses manage multiple facets of their...

Best Managed Service Providers...

In today's business world, managed services are more critical than ever. They can...