What does APIPA stand for?
APIPA stands for Automatic Private Internet Protocol Addressing. The fallback that gives a Windows host a self-assigned link-local address in 169.254.0.0/16 when no DHCP server answers. Seeing a 169.254.x.x address means the client could not reach DHCP; it can talk only on the local subnet.
APIPA is how a Windows computer gives itself an address when it is set to use DHCP and no DHCP server answers. It picks an address in 169.254.0.0/16, with the subnet mask 255.255.0.0, after checking that nobody else on the segment is using it. The standards name for the same mechanism is IPv4 link-local addressing. The address comes with no default gateway, so the computer can talk only to other devices on the same segment that also have 169.254 addresses. In practice it is a symptom: a 169.254.x.x address means the client could not reach a DHCP server.
APIPA in practice: an example
A user reports that the internet is down. The technician runs ipconfig and sees the address 169.254.37.112 with no default gateway. That one line says the PC asked for an address and got no reply, so the search moves away from the PC's own settings to the path to the DHCP server: the cable, the VLAN of the switch port, or the DHCP service itself.
What APIPA is confused with
APIPA vs DHCP: what is the difference?
DHCP is a server handing out addresses, with a gateway and DNS servers, from a pool the administrator defined. APIPA is the client's fallback when that server cannot be reached. What DHCP stands for
APIPA vs private IP addresses: what is the difference?
Private ranges such as 192.168.0.0/16 are assigned on purpose and are routed inside an organization. 169.254.0.0/16 is link-local: self-assigned and never forwarded by routers.
Which exams cover APIPA?
APIPA is on the official CompTIA acronym list for two of the four exams covered here.
- Network+ N10-009: 1.0 (Networking Concepts).
- A+ 220-1201 and 220-1202: 220-1201 2.0 (Networking).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. A workstation shows the IPv4 address 169.254.18.6. What does this indicate?
- It did not receive an address from a DHCP server
- It has a static public address
- It is the DHCP server
- Its DNS suffix is wrong
Show the answer
A. It did not receive an address from a DHCP server. Addresses in 169.254.0.0/16 are self-assigned when DHCP fails. The next step is to find out why the DHCP server cannot be reached.
2. Two PCs with APIPA addresses are connected to the same switch. What can they do?
- Communicate with each other but not with other networks
- Browse the internet through the default gateway
- Reach any host in the organization
- Nothing at all, because the addresses are invalid
Show the answer
A. Communicate with each other but not with other networks. Link-local addresses work on the local segment only. There is no gateway, and routers do not forward them.
Sources: RFC 3927: Dynamic Configuration of IPv4 Link-Local Addresses; Microsoft Learn: How to use automatic TCP/IP addressing without a DHCP server. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 12 November 2026.