Editing IPv4 (section)

===Link-local addressing===
RFC 3927 defines the special address block 169.254.0.0/16 for link-local addressing. These addresses are only valid on the link (such as a local network segment or point-to-point connection) directly connected to a host that uses them. These addresses are not routable. Like private addresses, these addresses cannot be the source or destination of packets traversing the internet. These addresses are primarily used for address autoconfiguration ([[Zeroconf]]) when a host cannot obtain an IP address from a DHCP server or other internal configuration methods.

When the address block was reserved, no standards existed for address autoconfiguration. [[Microsoft]] created an implementation called [[Automatic Private IP Addressing]] (APIPA), which was deployed on millions of machines and became a [[de facto standard]]. Many years later, in May 2005, the [[IETF]] defined a formal standard in RFC 3927, entitled ''Dynamic Configuration of IPv4 Link-Local Addresses''.