
196 Part Two • IPv6 Protocols
11.1 Anycast Overview
An experimental specification for IPv4 anycasting was defined in RFC 1546,
“Host Anycasting Service,” in 1993. That document suggested that another
address class could be carved out of the IPv4 address space for anycast
addresses. In that way, nodes could identify anycast packets simply by
looking at their destination addresses and treating them appropriately.
The motivation behind the RFC 1546 anycast experiment was to provide
nodes with a simpler way to reach any of a group of interchangeable
application servers. For example, rather than requiring a user to choose
a particular FTP server from a list, ...