
142 Part Two • IPv6 Protocols
identifiers for interfaces and sets of interfaces.” Three types of addresses—
unicast, multicast, and anycast—were defined, with unicast defined as “an
identifier for a single interface. A packet sent to a unicast address is deliv-
ered to the interface identified by that address.” Multicast and anycast
addressing will be discussed later in this chapter and in more detail in
later chapters.
Since 1995, the IPv6 addressing architecture specification has been updated
twice, firstin 1998, withthe publication of RFC 2373, “IP Version 6 Address-
ing Architecture,” and later with RFC 3513 in mid-2003. This section begins
with the basics ...