Evolution of the Address Space

IP and its addressing scheme evolved slowly, sometimes even erratically, over time. They were not, contrary to any current appearances, carefully designed prior to implementation! For example, RFC 1, published in April 1969, tells us that the original IP address space was specified at just 5 bits! As you will see in this chapter, that's enough for just 32 addresses! Strange as that might sound, in 1969 that was more than enough for the embedded base of computers that were being internetworked. Over time, the number of bits allocated to host addressing was increased to 6, and then 8, and finally up to the familiar 32-bit format that is in use today.

The actual format of the “IP address” evolved slowly over time in ...

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