Should you be worried that you’re still using IPv4?

Chances are, you’re reading this article because you have a little bit of knowledge. You probably also realize that you don’t have all the knowledge you need. So, rather than miss something, let’s take a quick detour through the basics of how the internet works. I’m going to try to keep it simple, so if you are a high-level sysadmin, you’ll probably realize that what I’m saying is in “the spirit” of truth but not always the incredibly technical definition of truth. That said, bring on the flaming comments if I really mess things up. OK? Let’s go.

And now, little bit of how the internet works

The internet works astoundingly well. From literally anywhere, on any connected device, you can send and receive data and you’ll get it with complete fidelity. How that happens is so complex that mere mortals can barely understand it. But, let’s focus on two aspects of the process: how information leaves your computer and where it goes.

Let’s talk TCP

There are two systems at work that determine how information gets from your computer to another computer or server, and how information from there gets back to you. The first is the Transmission Control Protocol, or TCP. TCP is, in effect, constantly creating jigsaw puzzles, breaking them apart, and reassembling new ones. When you send any sort of information, no matter how small, it’s broken up into little chunks called packets. These packets contain two things. First is the information that you want to send. Second is some control information so that the recipient knows it’s working.

Like I said, it’s akin to a jigsaw puzzle. Take a photo, cut it up into tons of pieces, and make them complex enough so that they only fit together one way. When someone gets them, they put it back together and they know they have the whole photo. As I said, I’m simplifying, but that’s just to help you understand.

And now, IP

Once your information is broken down into packets, those packets have to go somewhere. More importantly, they have to go to the right place. And that’s why every destination on the internet has an address. The Internet Protocol, or IP, is a way of assigning unique numbers to every location. All those packets are tagged with their eventual location, and they go on their way, using processes I’m not going to get into here.

TCP and IP work together so closely that they’re often referred to as a single thing: TCP/IP. But we’re not going to talk too much about TCP, it was just to help you understand a little bit. We’re going to talk about IP from now on.

IPv4, IPv6 and what that means

Throughout the history of the modern internet, we’ve been using version four of the internet protocol, abbreviated IPv4. IPv4 uses four sets of numbers, each from 0 to 255. That unique combination of four numbers lets the system define precisely 4,294,967,296 locations.

When the system was set up, certain rules went into place so there aren’t really 4 billion available locations, but there are still a lot. Evidently though, there weren’t enough. In 2017, the next version of IP, called IPv6, was ratified. Don’t ask me what happened to IPv5, because I don’t know.

IPv6 uses eight sets of four base-16 numbers, for a total of 340,000,000,000,000,000,000,000,000,000,000,000,000 possible addresses. Apparently this is larger than the number of stars in our field of vision. At any rate, it’s a lot. But, with great power comes… well… great confusion. IPv4 was fairly easy for humans to parse. A typical IPv4 address might look like 132.226.28.14, an IPv6 address might look like 2001:0db8:0000:0000:0000:8a2e:0370:7334. Look, most humans could probably remember an IPv4 address, but I really really doubt you could memorize more than one IPv6 address, if that.

Now, to the real question

Since 2018, many internet providers have switched from IPv4 to IPv6, at least in the way they communicate with each other. There’s an easy mathematical way to convert IPv4 to IPv6. Well, easy for computers. Not so easy for humans. The address above converts to :ffff:84e2:1c0e. If you can convert to base-16 in your head, you can see that each pair of numbers (except the ffff part) corresponds to a decimal. 84 in base-16 is 132 in base-10 for example. But let’s say the number of people who can do that on the fly without a calculator is pretty small indeed.

You can find out your own IP address by going to https://whatismyipaddress.com. You can find out someone else’s address by using a tool called Ping, or doing internet lookups. You will pretty much always find that the addresses you get are IPv4 addresses, not IPv6 addresses. Should you be worried?

The answer is simply, no. First of all, the traffic between your service provider and theirs is probably IPv6 already, and you just don’t see it. That’s the whole magic of the internet. A lot of it is totally invisible to normal humans. That’s done on purpose. The reason you’re seeing IPv4 addresses is that it’s easier for you to understand, and because the “last mile addressing” is IPv4. In other words, the traffic from the service provider to the individual computer is IPv4.

There’s no security risk involved in using IPv4 in this way. It’s safe and reasonable. At some point the whole world will convert to IPv6 and then it won’t work that way anymore. But for now, trust me you’re just fine.

Oh and by the way…

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About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.