Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » A »

APIPA - Automatic Private IP Addressing

Short for Automatic Private IP Addressing, a feature of later Windows operating systems. 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.

If the client is unable to find the information, it uses APIPA to automatically configure itself with an IP address from a range that has been reserved especially for Microsoft. 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.

APIPA is meant for non-routed small business environments, usually less than 25 clients.







TECH RESOURCES FROM OUR PARTNERS
DID YOU KNOW?
It's Happening Now: Perceptual Computing is Real

Perceptual computing is the ability for a computer to recognize what is going on around it. More specifically, the computer can perceive the... Read More »

Apple Pay Promises to Strengthen Payment Security

Experts believe that Apple Pay and other competitive payment systems will be far more secure than cards, even cards equipped with EMV chips. Read More »

The Great Data Storage Debate: Is Tape Dead?

Tape clearly is on the decline. But remember, legacy systems can hang for a shockingly long time. Read More »

QUICK REFERENCE
Network Fundamentals Study Guide

A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »

Computer Architecture Study Guide

This Webopedia  study guide describes the different parts of a computer system and their relations. Read More »

Webopedia Polls

The trend for the past two years has been for shoppers to spend more online during the holiday season. How do you typically shop for holiday... Read More »