Initially proposed in 1998, IPv6 has been used by developers since the early 2000s.
Logically, there was an IPv5 between IPv4 and IPv6.
However, version 5 never saw adaptation as a standard.
It was developed specifically to help stream video and is known as Stream protocol or ST.
However, like IPv4, it suffered from very limited available addresses.
IPv4 and IPv5 use 32-bit addressing.
Whereas IPv6 was upgraded to use 128-bit addresses instead.
This, among other issues, led to IPv5 being essentially skipped as far as implementation of protocols went.
Contents
Why IPv6?
One of the main limitations that IPv4 suffered from was the limited number of possible addresses.
The limitation of addresses in the IPv6 protocol is 2128.
Or 3.41038if you prefer SI notation, compared to 232in IPv4.
While IPv4 has just 4.3 billion possible addresses, 4,294,967,296 to be precise, IPv6 offers 340,282,366,920,938,463,463,374,607,431,768,211,456 possible addresses.
Thats 340 trillion trillion trillion.
This all but eliminates the issue of limited addresses.
Other improvements include handling more extensive data packets and simplified processing and configuration options.
A lot of the base functions that IPv6 comes with had to be additionally implemented for whichever time.
Which led to some complicated solutions for relatively simple-to-fix issues.
That said, IPv6 isnt as simple as being a better version.
It also brings with it a new set of issues that IPv4 lacked.
It is possible to run computers using both simultaneously in a configuration referred to as a dual-stack.
Dual stack devices are now the standard.
Though IPv6 may not be used if not actively supported by the ISP.
Most ISPs now actively support it, with some having the majority of their customers on IPv6.
Another thing to consider is the potential for repeating past design mistakes.
Rather than the modern CIDR design that optimizes the efficient use of the limited IPv4 address space.
Instead of using the area efficiently, there will be 264subnetseach with 264possible addresses.
Each with 4 billion times more possible addresses than there are possible IPv4 addresses.
This design decision was taken to simplify address allocation and route aggregation.
This had the added benefit of essentially acting as a firewall.
As unexpected incoming communications couldnt be translated to an internal host and were dropped.
Conclusion
IPv6 is the successor to the long-standing IPv4 addressing scheme of the Internet.
IPv4 needed replacement because its limited address space was at risk and has now been exhausted.
