Although Internet Protocol version 4 (IPv4) is the most common version of IP today, Internet Protocol version 6 (IPv6) is the newest version and ultimately replaces IPv4. IPv4 addresses were allocated to specific geographic regions in 2011. IPv6 uses 128-bit addresses supporting 340 undecillion addresses. For those unfamiliar with an undecillion, this translates to 340 times 10 to the 36th-power possible IP addresses.