Learn About Internet Protocol Version 6 and Your Devices

What Is Internet Protocol Version 6 and Why It Matters

Internet Protocol Version 6, commonly called IPv6, is a system that allows devices to communicate across the internet. To understand IPv6, it helps to know what came before it. Internet Protocol Version 4, or IPv4, has been the standard way devices talk to each other online since the 1980s. However, IPv4 has a significant limitation: it can only create about 4.3 billion unique addresses. Each device that connects to the internet needs its own address, similar to how every house needs a street address for mail delivery.

In the early 2000s, technology experts realized that the world was running out of available IPv4 addresses. As more smartphones, computers, tablets, and internet-connected devices entered homes and businesses, the supply of addresses dwindled rapidly. According to the American Registry for Internet Numbers, the final available IPv4 addresses were distributed to regional registries in February 2011. After that point, no new IPv4 addresses could be created.

IPv6 solves this problem by using a much larger addressing system. While IPv4 uses 32 bits to create addresses, IPv6 uses 128 bits. This means IPv6 can create approximately 340 undecillion addresses—that is 340 followed by 36 zeros. This enormous number means there are enough unique addresses for every device that may ever exist, with trillions of addresses left over for each person on Earth.

The shift from IPv4 to IPv6 is one of the largest infrastructure changes in internet history. As of 2024, major internet service providers and technology companies continue the transition. Google reports that approximately 40% of users can already access its services through IPv6. This transition affects how your devices connect to the internet, though most users do not notice the change happening behind the scenes.

Takeaway: IPv6 is the newer internet addressing system created because IPv4 ran out of available addresses. IPv6 provides vastly more addresses, allowing for continued growth of internet-connected devices worldwide.

How IPv6 Addresses Work and Their Format

An IPv4 address looks like this: 192.168.1.1. It consists of four numbers separated by periods, with each number ranging from 0 to 255. These are called octets because each section contains 8 bits of data. Once you see a few IPv4 addresses, they become relatively easy to remember and recognize.

An IPv6 address looks dramatically different. Here is an example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. IPv6 addresses use hexadecimal notation, which includes the numbers 0 through 9 and the letters A through F. The address contains eight groups of four hexadecimal digits separated by colons. Because IPv6 addresses are so long, several shorthand methods have been developed to write them more briefly.

One shorthand rule allows you to remove leading zeros from any group. So 0000 becomes just 0, and 0db8 stays as db8. Another rule allows consecutive groups of zeros to be replaced with a double colon (::). This can only be used once in an address. Using these rules, the long address above can be written as 2001:db8:85a3::8a2e:370:7334.

IPv6 addresses also contain information about the device and its network location, similar to IPv4. The first portion of the address identifies the network, while the remaining portion identifies the specific device. For example, the first 64 bits typically identify the network, and the last 64 bits identify the device interface. This split makes it easier for routers to direct traffic efficiently across the internet.

Different types of IPv6 addresses serve different purposes. Unicast addresses are used for regular device-to-device communication, much like most IPv4 addresses. Multicast addresses allow one message to be sent to multiple devices at once, which is useful for video streaming or software updates. Link-local addresses allow devices on the same physical network to communicate without needing a router or internet connection.

Takeaway: IPv6 addresses are much longer than IPv4 addresses and use hexadecimal notation with colons as separators. Learning the format helps you recognize IPv6 addresses when you see them in network settings or documentation.

Which Devices Support IPv6 and How to Check Your Equipment

Most modern devices support IPv6, but the level of support varies. All major operating systems released in recent years include IPv6 capability. This includes Windows 10 and Windows 11, macOS versions from the last ten years, iOS, Android, and most versions of Linux. However, older devices may not support IPv6, and some devices may have IPv6 capability that is not fully activated or configured.

To check if your computer supports IPv6, you can use built-in system tools. On a Windows computer, open the Command Prompt and type "ipconfig /all" then press Enter. Look through the results for a section labeled with your network connection name. If you see an entry that starts with "IPv6 Address:" followed by a long hexadecimal address with colons, your device has IPv6 support. On a Mac or Linux computer, open Terminal and type "ifconfig" or "ip addr show." Again, look for entries that contain colons and hexadecimal characters, which indicate IPv6 addresses.

Smartphones and tablets typically have IPv6 support built in. For iPhones and iPads, go to Settings, then Wi-Fi, tap the information icon next to your network name, and look for IPv6 Address in the list. The presence of an address means your device supports and is currently using IPv6. For Android devices, go to Settings, select About Phone or About Tablet, then look for IP Address or IPv6 Address information. Many Android phones display both IPv4 and IPv6 addresses simultaneously.

Your internet router also needs to support IPv6 for your devices to use it properly. Routers manufactured in the last eight to ten years typically include IPv6 support, though it may need to be turned on in the settings. Check your router's manual or manufacturer website to find information about IPv6 support. If your router is older than ten years, it may not support IPv6. Contact your internet service provider to learn what routers they recommend for IPv6 connectivity.

Some devices may show an IPv6 address but still primarily use IPv4 for internet traffic. This is normal during the transition period. Both protocols can run simultaneously on the same device. This dual-stack capability allows devices to communicate using whichever protocol the destination device prefers.

Takeaway: Most devices made in the last ten years support IPv6. You can check your device's IPv6 support using system settings or command-line tools. If your device shows an IPv6 address, it is ready to use the newer protocol.

Internet Service Providers and IPv6 Availability in Your Area

Internet service providers, or ISPs, control whether your home or business receives IPv6 connectivity. Even if your devices support IPv6, you need an ISP that offers it and a router configured to request IPv6 addresses. Major ISPs in the United States have been rolling out IPv6 support gradually since the early 2010s. As of 2024, most large ISPs offer IPv6 to at least some of their customers, though coverage is still not universal.

Comcast, one of the largest ISPs in the United States, offers IPv6 to residential customers in many areas. Verizon Fios also provides IPv6 support to a growing percentage of customers. Charter Communications and Cox Communications have deployed IPv6 in various service areas. However, the availability depends on your specific location and service plan. Smaller regional ISPs and rural providers may have slower IPv6 adoption.

To find out if your ISP offers IPv6, contact their customer support directly. You can also visit your ISP's website and search for "IPv6" to find information about availability and how to request it. Some ISPs automatically provide IPv6 to all customers, while others require you to request activation or upgrade your modem and router to newer models that support the protocol.

ISPs outside the United States have varying levels of IPv6 deployment. European ISPs tend to have implemented IPv6 more widely than North American providers. Asian ISPs, particularly in countries like Japan and China, have also invested heavily in IPv6