Why We Needed IPv6
Understand the address shortage that drove the move to IPv6.
IPv4 Ran Out of Room
IPv4 offers about 4.3 billion addresses (2^32). When the protocol was designed in the 1980s that seemed limitless, but the explosion of phones, laptops, and smart devices consumed them.
By the 2010s, the regional registries that hand out addresses had exhausted their free pools, forcing a long-planned move to IPv6.
A Vastly Larger Space
IPv6 uses 128-bit addresses instead of 32-bit. That is 2^128 addresses — roughly 340 undecillion, a number with 39 digits.
The supply is so enormous that every device on Earth could have countless addresses. Address exhaustion, the core IPv4 problem, simply disappears with IPv6.
IPv4: 2^32 ~= 4.3 billion
IPv6: 2^128 ~= 3.4 x 10^38