Mind your Fours and Sixes: Common Questions about IPv4 and IPv6

Mind your Fours and Sixes: Common Questions about IPv4 and IPv6

Since we started the Team ARIN microsite, there have been a few common misconceptions that we have seen repeatedly in news coverage about IPv4 and IPv6. The good news is that there is a ton of great information out there, but at times it can be overwhelming. So we thought we would take a moment and boil it down to the facts you really need to know.

What is the difference between IPv4 and IPv6?

IPv4 uses 32-bit addresses, which means there are “only" 4,294,967,296 possible unique addresses. That seems like a lot until you look at IPv6, which uses 128-bit addresses, allowing for a grand total of 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undicillion unique addresses!

What devices get an IP address?

Every device directly connected to the Internet has an IP address, including every computer, cellular telephone, gaming console, and that isn’t all. Many new household appliances and other devices have IP addresses, and this trend is expected to continue to rise.

What do I have to do to get ready for IPv6?

Home Internet users will be reliant on their Internet Service Providers (ISPs) to make the necessary changes at the network level. IPv6 will not raise compatibility issues for web users with old computers, nor will it create speed or security issues; it may even improve both. By and large, consumers should not have to purchase new hardware. Nearly all major manufacturers’ routers, computers, even wireless phones produced in the last several years are IPv6-capable, but they may need to be configured properly by each business. Some businesses with very old equipment may need to replace it with IPv6-enabled devices.

What does this mean for Domain Names?

Absolutely nothing! The Internet is not running out of domain names. A domain name, such as www.arin.net, maps to a specific IP address like This is an addressing system change that has nothing to do with the actual URLs that consumers type in to access web pages.

Is my Internet going to crash because of the transition from IPv4 to IPv6?

No. The Internet will not “crash" because not everyone is running IPv6. However, some organizations will have limited connectivity to new users and may experience performance issues with any services (such as audio and video streaming) that are not IPv6 enabled. The Internet is a big place, with lots of options. If a home user can’t access something they want, they will find somewhere else to get it. If businesses want to meet the needs of all potential customers, they will be sure that they can be reached over IPv4 and IPv6.

These are just a few of the questions that crop up on a regular basis. To learn more, you can check out our education section for additional materials and head over to http://www.getipv6.info for the lowdown on getting your organization IPv6-ready!

Post written by:

Sean Hopkins
Senior Policy Analyst, ARIN

Recent blogs categorized under: IPv6

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