What is IPv6?

It’s World IPv6 day. So what? So a bunch of transistorheads are having a party. Is that all there is to it?

Actually today marks the biggest accomplishment since the internet came into being. As of today, the whole backbone of the internet is running on a new system called IPv6. IPv6 guarantees that we can connect as many things to the internet as we want without running out of unique ways to find them. It’s a massive undertaking and this is a big step.

What’s really amazing is that it’s all been done without taking the internet offline. This morning you woke up, checked your e-mail or facebook status, and didn’t even realize that things had changed. No hysteria, no fits, it just worked.

But what is IPv6?

Everything connected to the internet needs an address, whether it is a computer, printer, smartphone, Blu-ray player, satellite receiver… everything. Internet addresses are like real addresses; they’re unique to each thing. And just like each city can have a Main St. without causing problem for Main Streets in other cities, we use routers to make sure the computers in our homes and offices can use common addresses without affecting other homes and offices. Even with that, the 42 million available addresses are already used up.

So… we need more. The scientists who sit around and think of this stuff say that we need 340 crash-bang-zillion of them. No seriously, this is a number so big that there isn’t even a word for it. Imagine the number 340 with 32 more zeroes at the end. That’s a lot of addresses.

The old system was called IPv4 and the addresses looked like this:

That’s a set of four numbers, each from 0 to 255. An IPv6 address looks like this:


Obviously there are a lot more numbers there. There are eight sets of numbers, and each one can be from 0 to 65,535. Because computer geeks never make it easy for regular folk, the numbers are expressed in base 16. Sometimes you’ll see two colons next to each other because if one of the sets of eight numbers is zero, you can just ignore it.

The good news

The good news is that you can keep ignoring IPv6, just like you ignore IPv4. The internet works with a system called DNS that translates the addresses you type like http://www.solidsignal.com into numbers. Now, the new system will translate your request into IPv6 whenever possible.

The transition’s not over until every device on the internet is using IPv6 and only IPv6. That will probably be years. In the meantime, the good news is that everything will keep on working.

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.