The Legacy Internet is Out of Addresses: What Apple is Doing

We knew this time would be coming. The old Internet address protocol would run out of addresses. After all, there are only 4.3 billion to go around, and they're pretty much used up. Here's an update on what Apple is doing to support the new address scheme.

The original Internet address space, referred to as IPv4, provides for 232 (4.29 billion) addresses. You've probably seen examples of those addresses on your Mac and iPhone, for example,, where each of the numbers can be from 0-255.

With the Internet of things, the proliferation of small Internet devices and the adoption of smartphones all over the world, those addresses have been almost all used up, something the originators of the TCP/IP protocol never envisioned in the 1980s.

In time, however, it was realized that we would need a lot more addresses, and in 1999, a new protocol was established called IPv6. The developers of that protocol were determined that we'd never have to go through this painful expansion again, and so IPv6 provides for 2128 (3.4 x 1038) addresses. One of those address, in hexadecimal notation (to make it shorter and more readable) might look like: FE80:0000:0000:0000:0202:B3FF:FE1E:8329. To put that in perspective, each grain of sand on the planet Earth could have more than a billion billion addresses.

One nice feature of IPv6 is that, because there are bilions and billions more IPv6 addresses than stars and planets in the universe, and because a user's address can be periodically rotated, it becomes impractical to identify a specific computer and do port scans looking for weaknesses.

Apple's Plan

At WWDC in June, Apple's Sebastien Marineau-Mes reminded us that OS X has been supporting IPv6 for more than a decade. iOS has always supported IPv6. In the WWDC State of the Union message on June 8, Mr. Marineau-Mes told developers (at 35m20s) that 1) the depletion of IPv4 addresses is imminent, 2) major carriers are moving to 100 percent IPv6 networks and 3) apps submitted to the App Store starting with iOS 9 would be required to support IPv6.

Apple's Sebastien Marineau-Mes at WWDC. Image credit: Apple

The details of how the developers do that need not detain us here. Basically, if the developer uses Apple's networking framework, the work will be done for them. Developers just need to be careful about certain issues, such as not pre-flighting their app with an IPv4 connection or using hard coded IPv4 address. Apple has even provided a way for developers to set up an IPv6 hotspot on their Macs to test app compatibility with an IPv6 network.

The Demise of IPv4

Even though IPv4 addresses are in very short supply, equipment and servers that use that protocol will still be with us for many years. (By the way, the organization that administers those addresses in the U.S. is the American Registry for Internet Numbers (ARIN), one of five worldwide Regional Internet Registries, RIRs.)

The goal of the Internet technical community has been, all along, to provide for a graceful transition and make everything transparent to customers. Accordingly, there isn't anything you really need to do prepare for the gradual change over except to be aware of what those long addresses mean and continue to upgrade your OS X, iOS and apps.

As part of this process, ISPs have been gradually replacing home cable modems with what's called "DOCSIS 3" class devices. (Data Over Cable Service Interface Specification) These new cable (and DSL) modems are capable of handling both IPv4 and IPv6 protocols. What's left for the home customer is to be aware if IPv6 is available from their ISP in their neighborhood and be ready to, in time, upgrade their main home router (if a router isn't already merged into the new cable modem) to support the IPv6 protocol. For example, Comcast has a list of cable modems and routers it has tested for use with IPv6. Fortunately, Apple's Airport Extremes Gen 4,5, and 6 all work fine as both primary routers and Wi-Fi base stations.

An important thing to remember is that these modern modems and routers will still work with your older home devices such as DVD/Blu-ray players, smart TVs, Apple TV, Roku, etc that only need to operate as IPv4 devices on a home network. See reference #1 below.

This transition on the network side is, I think, going very smoothly and is designed to be transparent ot the user. Apple has made sure OS X and iOS devices are ready to support the gradual transition. All customers need to do is make sure they don't invest in discount, obsolete home networking gear so that they can take advantage of IPv6 as this more secure, capable protocol emerges to become more and more dominant.

More Information

For those who want to learn more of the details, I recommend these articles.

1. If you'd like to learn more about the transition from IPv4 to IPv6 and how it applies to you, see: "A Layman’s Guide to the IPv6 Transition."

2. If you'd like to learn more about what Apple told developers at WWDC, how its implementation differs from Android and the details of how the Internet is rapidly adopting IPv6 see: "Apple to iOS devs: IPv6-only cell service is coming soon, get your apps ready."

3. For some background on the state of IPv4 address depletion, see: "5 Misperceptions about ARIN IPv4 Depletion."

4. If you're curious about how to check on the IPv6 address of your iOS or OS X device, see "How to Obtain the IPv6 Address of Your Mac and iPad."

5. Finally, if you're confused by some of the network nomenclature thrown around in these discussions, a very helpful article, with explanations and nice charts, is: "Understanding IP Addressing and CIDR Charts."


Teaser images via Shutterstock.