Temporary addresses [edit]
The globally unique and static MAC addresses, used by stateless address autoconfiguration to create interface identifiers, offer an opportunity to track user equipment—across time and IPv6 network prefix changes—and so users.[34] To reduce the prospect of a user identity being permanently tied to an IPv6 address portion, a node may create temporary addresses with interface identifiers based on time-varying random bit strings[35] and relatively short lifetimes (hours to days), after which they are replaced with new addresses.