Editing IPv6 (section)

===Link-local address===
[[File:IPv6 link local unicast address structure-en.svg|thumb|The Link-Local Unicast Address structure in IPv6]]

All interfaces of IPv6 hosts require a [[link-local address]], which have the prefix {{IPaddr|fe80::|10}}. This prefix is followed by 54 bits that can be used for subnetting, although they are typically set to zeros, and a 64-bit interface identifier. The host can compute and assign the Interface identifier by itself without the presence or cooperation of an external network component like a DHCP server, in a process called ''link-local address autoconfiguration''.{{Citation needed|date=January 2022}}

The lower 64 bits of the link-local address (the suffix) were originally derived from the MAC address of the underlying network interface card. As this method of assigning addresses would cause undesirable address changes when faulty network cards were replaced, and as it also suffered from a number of security and privacy issues, {{IETF RFC|8064}} has replaced the original MAC-based method with the hash-based method specified in {{IETF RFC|7217}}.{{Citation needed|date=January 2022}}