IPv4 vs IPv6 and the missing IPv5

30.04.2019 1,549 0

The time of IPv1, IPv2 and IPv3 is long gone. The latest edition of the protocol is IPv6, but almost in every setting menu, you have an option for IPv4. Why? Using an older version is not that strange, but why not IPv5 vs IPv6? How is it possible for the IPv4 protocol from the 80s to be still alive? Let’s take a look!

IP (Internet Protocol)

IP is the internet protocol that we all use. It allows our devices to connect to the Internet. It is a description, a set of rules that determine the way data goes from a client, all the routes to the host and back. The IP addresses serve to identify all of the connected devices. They are unique.

In the beginning, the IP protocol was part of another one – TCP/IP. It took 3 revisions of this protocol for the IP to be separated from the TCP/IP. The first independent IP was version 4 – IPv4.


You are probably familiar with the IPv4. It looks like this – There are 4 groups of numbers between 0 and 254. They are separated by dots. In total, there are 4 294 967 296 IPs! A tremendous number, don’t you think so? Yet, when we think about how many devices are there, and most of them are connected to the internet, we can see that it is not enough. The internet providers use clever ways to reuse the IPs, but this can’t last forever. Here the new standard kicks in.


IPv5? No! This one was skipped. It never got to be a real standard and died during development. It wasn’t much of an improvement compared to IPv4. It was regarded as a streaming protocol and got a few years of development, with the last version being ST2 (second version). In the end, it was abandoned together with the name. The next standard was announced later and it was the IPv6.


The new protocol was a huge upgrade. The IPv4 uses 32-bit addressing, and the new version skipped the 64-bit addressing and got directly to the 128-bit addressing. A bit of an overkill, but that way this standard can last a long, long time.

Example of an IPv6 address: “2001:0db8:0000:0041:0200:8a2e:0370:7344”.

Here the groups became more – 8. Each of them has 4 hex (hexadecimal) digits and they are separated by colons.

That way there is plenty of more combinations. To be exact, 1028 more times than IPv4!

Apart from the possibility to connect an incredible amount of devices, the new protocol is more secure. It uses IPsec – internet security protocol. It is an authentication method that encrypts the data with Encapsulation Security Payload.

Other benefits of IPv6 are the improved routing without fragmentation of packets; updated header structure with less processing overhead; SLAAC – stateless address auto-configuration.

The only reason we haven’t switched completely to IPv6 is the cost to upgrade. ISPs are doing it, but at a slow pace. At the end of March 2019 the global adoption statistic of Google showed 22.62% with Belgium being the front-runner with 52.52%.

IPv6 will definitely replace IPv4 forever. It will just need some time after which it will be the only IP standard for very long.

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