thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Networking Fundamentals · Foundational

Automatic Private IP Addressing (APIPA)

A Windows feature that self-assigns an address from 169.254.0.0/16 when a DHCP server cannot be reached.

Definition

APIPA implements IPv4 link-local addressing (RFC 3927): the host picks a random 169.254.x.x address, checks it with ARP, and uses mask 255.255.0.0 with no default gateway. Hosts with APIPA addresses can communicate only with other link-local hosts on the same segment. The usable range is 169.254.1.0 to 169.254.254.255.

Example

ipconfig showing 169.254.33.7 means the PC did not get a DHCP lease.

Exam tip

A 169.254.x.x address is the classic exam clue for a DHCP failure: check the DHCP server, scope, relay or cabling.

Related terms