IPv6#

IPv6 gives us 16 **trillion* IP address per square inch of the Earth's surface.

This is the number of possible IPs: 340,282,366,920,938,463,463,374,607,431,768,211,456 - that's a lot of decimal places.

This new standard of IP address resolves the issues we're facing with the IPv4 standard: running out of addresses. But IPv6 also addresses a lot of other problems too. For now I want you to understand just two things: IPv6 and IPv4 are incompatible with each other; and an IPv6 address has a completely different format to an IPv4 address.

IPv4 and IPv6 addresses don't operate together. There is nothing in the standard that allows an IPv4 address to be translated to an IPv6 address. This might not seem obvious at first, but remember that an IPv4 address is 32-bits of information and an IPv6 address is 128-bits. There isn't enough information inside of an IPv4 address for you to construct an IPv6 address.

With this in mind, IPv4 and IPv6 aren't used directly together but instead are "translated" between each other using hardware/software that does some sort of translation or routing. This isn't something you'll need to be concerned with at this point in time.

Here's an example IPv6 address: 2001:0db8:0000:0000:0000:ff00:0042:8329. Yikes! Here's another one: ::1. Weird.

IPv6 has rules about how an IP address is written out and what can be omitted. For example with the first address above you can omit all the octets that are just filled with zero (0s) and also remove the zeroes from the beginning of the octet: 2001:db8::ff00:42:8329.

At the time of writing you can safely ignore IPv6 and just be aware of two things: you cannot interoperate IPv4 and IPv6; and IPv6 addresses are 128-bits in length and have a different format and set of rules for writing them. You'll also notice the lack of a CIDR range - that's because IPv6 networks are easier to subnet than IPv4, but again keep this simple at this point in time.