APIPA (Automatic Private IP Addressing) is a Microsoft Windows feature used when a DHCP server cannot be contacted, the computer will automatically assign itself an address in the 169.254.0.0/16 range. This is known as Link-Local in IPv6.
In computer networking, a link-local address is a unicast network address that is valid only for communications within the subnetwork that the host is connected to. Link-local addresses are most often assigned automatically with a process known as stateless address autoconfiguration or link-local address autoconfiguration, also known as automatic private IP addressing (APIPA) or auto-IP.
Link-local addresses are not guaranteed to be unique beyond their network segment. Therefore, routers do not forward packets with link-local source or destination addresses.
IPv4 link-local addresses are assigned from address block 169.254.0.0/16 (169.254.0.0 through 169.254.255.255). In IPv6, they are assigned from the block fe80::/10.: 2.4