The feature is new in the Solaris Express 11/03 release.
By default, the interface ID of an IPv6 address is autoconfigured with the interface's hardware-specific address. For example, if the interface is an Ethernet card, its interface ID is autoconfigured from the interface's MAC address. However, some system administrators might need to keep private the hardware-specific addresses of one or more interfaces on a node.
The IPv6 Temporary Addresses feature implements the privacy extensions standard that is defined in RFC 3041, “Privacy Extensions for Stateless Autoconfiguration in IPv6.” The temporary address feature enables administrators to assign randomly generated, modified EUI-64 format interface IDs to interfaces of an IPv6 node. In addition, the administrators can specify a time limit for the lifetime of a temporary address. After configuration, the IPv6 daemon in.ndpd automatically generates the temporary interface ID for the interface, in addition to the automatically generated, MAC address-based interface ID.
For further information, see the System Administration Guide: IP Services.