Address Space
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... LAN technologies, it became
obvious that this assumption was wrong and the separation of the
address space into three classes (Class A for a few huge networks ...
... network number (Class A, B, or C) into pieces, allowing a
higher utilization of address space, and thus promoting conservation
of the IPv4 address space. Because of the built-in notion of
...
... Addresses are
increasingly thought of as bitwise contiguous blocks of the entire
address space, rather than a class A,B,C network. For example, the
...
... address
registries to delegate realistic address spaces to organizations and
be unfettered by the traditional network classes ...
... allocated and assigned in a hierarchical manner, and the CIDR'ization
of large portions of the address space which were assigned according
to the guidelines of RFC 1466(-> 2050) resulted in a significant drop of
...
... Internet sites. During the earliest days of the IANA, given a vast
address space, the requirements for assignments of network address
space ...
... address space, the requirements for assignments of network address
space were much less stringent than those required today.
Organizations were essentially assigned networks based on their
...
...
The upper half of the Class A address space (64.0.0.0 - 126.0.0.0)
(127.0.0.0 has traditionally been used by the Unix operating system
...
... IANA for growth within the IPv4 address space. Of the lower
half of the address space, 22 were assigned pre-1982, 6 were assigned
between 1982 and 1987, 26 were assigned between 1988 and 1992, and 2
were assigned between 1993 and 1995. In May of 1995 four Class ...
... outlined in RFC 1466(-> 2050). 61.65% of the Class B address space is
currently allocated. The class B address space ...
... address space is
currently allocated. The class B address space is 25% of the total
IPv4 address space.
...
... 1466(-> 2050) the allocation of Class C
address space has skyrocketed since 1993. 27.82% of the Class C
address space ...
... address space has skyrocketed since 1993. 27.82% of the Class C
address space is currently allocated. The class C address space is
...
... address space is currently allocated. The class C address space is
12.5% of the total IPv4 address space.
...
...
Of the remaing 12.5% of the address space, the lower 6.25% is
allocated for multicast applications (mbone, OSPF ...
... is allocated and the remainder is reserved for future growth. It
should be noted that careful extrapolations of the current trends
suggest that the address space will be exhausted early in the next
century.
...
... Internet service providers were given blocks of the Class B
address space to distribute to customers. This space was often
provided to clients ...
... encouraged to return those addresses. Similarly to those sites who
are using a small percentage of their address space and who could
relatively easily remove network ...
... (128/2) space. Some customers who are only using a percentage of
their address space (assuming they are subnetting using contiguous
bits) may be willing to allow usage of the upper portion of their
...
... bits) may be willing to allow usage of the upper portion of their
assigned address space by their providers other customers.
...
... How to Return a Block of Address Space to the IANA ...