What is an IP? What is IPv4 and IPv6? What happened to IPv5? #AskRushil

I added the hashtag for fun. No one really uses it (but please, be my guest).

I get this question often on my online alias, AmusingThrone. People are often trying to figure out what does it mean to get an IPv4 or IPv6 address from Cloud Hosting, or they occasionally check their IP online, and are puzzled by why they see numbers on one network, and see numbers and letters on the other.

Let's start small. What is an IP address? IP, short for Internet Protocol, is your identifier or your "phone number" while interacting with the Internet. Most likely, when you search Google for your IP Address, you get a series of numbers looking something like this:

131.150.44.138

Every device connected to the internet, whether it your smartphone, computer, Tesla, TV, anything, is assigned at least 1 IP Address. Most often, this is the IP Address assigned to you by your ISP, or Internet Service Provider.

Like I said earlier, consider it like your "phone number". Through your IP Address, you can identify the location and the device(s) assigned to it. But just like a phone number, that location can be spoofed (having an area code of New York but living in San Francisco), and can be easily changed, granted there are more numbers available.

Not too complicated right? Well it shouldn't be, after all it was meant to be straightforward. So where does IPv4 and IPv6 come in all this?

IPv4 is an internet protocol developed in 1981. I won't go into to much details on how it works, because that extends the scope of this post. Here is what you really need to know: IPv4 used 32-bit (4-bytes) addresses. That means there are around 4.3 billion (2^32) types of IP address that could be generated. 18-million addresses are reserved for internal private use, and an additional 270 are reserved for multicast use, bringing us to around 4 billion addresses. While it still seems like a large number, the sheer amounts of new network devices interacting with the Internet has exhausted that number.

In fact, in the September of 2015, the American Registry for Internet Numbers (ARIN), the organization responsible for issuing IP addresses in North America, ran out of freely available IPv4 addresses. The latest report from IANA, the Internet Assigned Numbers Authority shows that there are only 7.81 million IP Addresses available globally (as of September 2018).

That seems like a huge problem, and we have been aware for a long time that something like this was going to happen. That is why in 1990s, IPv6 was released. It has had a slow adoption phase throughout the years.

There are a few technical differences between IPv4 and IPv6 (such as checksum calculations), but they essentially work the same. The difference? IPv6 has a significantly larger number of available IP Addresses.

IPv6 addresses are 128 bits (16 bytes) long. Therefore, there are around 3.4 undecillion (2^128) amount of IP addresses available. The IPv6 use hexadecimal digits. That means instead of zero through 10 (base 10), it can use zero through 10 and ‘a’ through ‘F’ (base 16). You may have seen these when searching for your IP on your cellular network:

2787:36c2:3fc5:9d2a:6f6d:5fef:8813:d068

So you may have been wondering what happened to the numbers 0, 1, 2, 3 and 5? Well, versions 0-3 were all private tests that were never released to the public, but version 5 was well, sorta released. IPv5 was officially released as the Internet Streaming Protocol, and was developed to stream video and voice data. The primary issue was that it faced the same limitations as IPv4, so it was pretty much abandoned as soon as the initial proposals for IPv6 were released. However, work on the IPv5 transitioned into what we call VoIP today.

So what does that mean for you as the consumer? Nothing really. The world is probably going to be continuing to use IPv4 for a very long time. Trust me, it's not going anywhere.

It all started with techniques like Classless Interdomain Routing (CIDR) and Network Address Translation (NAT). We have been prolonging IPv4 on life support for years - and that is ok. Why? Because the move needs to be slow, else we risk having the internet divided between IPv4 and IPv6 sites. Imagine an Internet in which you could only interact with certain sites depending on the Internet Protocol you had.

After the initial eye-opening realization that we are going to need to move to IPv6 within the next decade, ISPs have started working on new solution, such as NAT64. These new solutions will help you transition to IPv6 while still allowing you to interact with sites using IPv4. Hopefully, within the next 5-10 years, every consumer will be on IPv6.

I encourage you to check if your ISP supports NAT64 with IPv6 and IPv4 and making the switch today. The more people aware of this important switch, the more the industry will adapt. Most American ISPs already support this.

But to answer the original question, should you pay the extra $ to your Cloud Provider for an IPv6 Address? It really depends on what you are doing. If you are trying to start a business in the online world, then yes. But if this is a small time gig, then don't bother - you won't need it. But invest in IPv6 early, that way you won't have to transition when things become much larger and harder.

That's all from me. Feel free to reach out if I missed anything, or need clarification on something.

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