IANA
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... addresses to
Internet sites. During the earliest days of the IANA, given a vast
address space, the requirements ...
... network, and is thus unavailable) has been reserved
by the IANA for growth within the IPv4 address space. Of the lower
half of the address space ...
... Class A
networks previously assigned have been returned to the IANA. All
remaining Class A addresses ...
... CIDR, some 50,000 networks
were assigned by the IANA, yet only a small percentage (30-40%) of
the sites actually had connections to the global Internet ...
... various ways and steps. Some sites, through a little (or in some
cases no) work, could donate unused IP nets back to the IANA.
...
... Internet community
would like to encourage you to return those addresses to the IANA or
your provider for reapportionment.
...
... security reasons will always be isolated,
consider returning the address assignments to the IANA or your
provider and utilizing prefixes ...
... to advertise more routes or request additional address blocks from
the IANA or their upstream provider.
...
... networks
which fall outside of their normal address blocks back to the IANA or
the appropriate registry.
...
... How to Return a Block of Address Space to the IANA ...
... Class A networks have been
returned to the IANA. This may not seem significant but those 4
networks represent over 1.5% of the total IPv4 address ...