It’s something people don’t want to talk about. Something we all forget amongst the other threats to our world and society – climate change, pollution, war, genocide. They’re all extremely important causes to be sure. But what if the internet halted? That is part of the threat we are dealing with. It won’t be a virus or terrorist attack or global meltdown of basic services. It’s built in to the internet’s design.
The Internet was built in layers – levels of protocols meant to exchange “packets” (small bundles of data) between devices assigned IP addresses – like a phone number for devices connected to the internet. Anyone who has a computer, phone, or game console connected to the internet has an IP address. Chances are you’ve seen one without realizing it – numbers like 127.45.145.23 (a completely random example). IP addresses are based on the protocol IPv4 which was released with the internet back in the early 90s when consumers could access it. A large number of IP addresses were bought by corporations and government interests to be reserved for special use. A large number were also bought by ISPs like Comcast, America Online, and Earthlink to name a few. And today we all have IP addresses for every connected device. But we won’t very soon. IPv4 is a 32-bit address system, which means that it can support up to 2^32 unique addresses or about 4.3 Billion addresses ranging from 18.104.22.168 to 255.255.255.255 and every possible combination in between (though a large portion of the address space is heavily reserved).
Now 4.3 Billion addresses seems like a ton. Even if ever person in the United States had 2 internet connected devices – that would only be 600 Million addresses. However, this is obviously not the case. A study conducted a few years ago estimated there are over 1.5 Billion internet users across the world, and many more devices that are using IP addresses. As I look around my room, I have at least 4 devices using an IP address. In my house there are probably another 5 devices that all have their own IP addresses as well. Since the average US household has far more than 2 devices for every person, we can see there are far more than 600 Million IP addresses being used in the US alone. Not to mention the vast amount of owned IP spectrums used in servers, ISPs, and corporations. A few technologies were developed over the years to stave off the strain on IP address use. One, called a subnet mask, applies a general IP address to a network of several other devices. This means that when you access a website or remote server on a device in a subnet mask, the responding server sees only the subnet, and then the router in your home sends the information to the proper device to view your information. The way subnetting actually works is a little confusing, but in general it takes you IP address – lets say 127.45.145.23 and applies a subnet like 255.255.255.0. Through subnetting, servers will see your device as 255.255.255.23. To make a complicated story short and simple, this allows more IP addresses to be stuffed into a single site and reduces the demand on each address. A second technology, called Network Access Translations or NAT, you’ve probably used if you’ve ever connected to the internet in a Starbucks. It applies a public IP address to all connecting devices and again, the router sorts through which device gets the proper information. All of this has been done to sort through and simplify how networks connect to devices.
And yes, if you are terribly confused, don’t worry. Networking is one of the most complicated areas in computing and in no way my specialty. The thing to draw here is that engineers have worked desperately to cover up the limitations and eventual exhaustion of IP addresses. By 2011 by most estimates we will be out of usable addresses. What happens then? Well, it becomes extremely difficult to allow new devices on the internet without the extensive use of NAT and subnets. That adds complication to networking infrastructure and requires more hardware to communicate between the internet proper and local networks.
That is why IPv6 was developed. IPv6 is a 128-bit system, which would allow every human on earth to have as many IP addresses assigned to them as there are IPv4 addresses with trillions of addresses left over. It’s such a vast amount that it would be virtually inexhaustible. The marvel of IPv6 is that even though it’s a larger amount of numbers, it would vastly simplify networking. When every device can have a truly unique address, we no longer need NAT or subnets, we don’t need the older forms of network translations. Servers can directly access an IPv6 address across the internet without going through levels of masking. IPv6 addresses are written in hexadecimal notation, also known as base 16. So an IPv6 address might look like this: 2001:db8:85a3::8a2e:370:7334. It looks more confusing but in application it is vastly better. Subnet masks can still and will be used for larger networks like in business servers simply for ease of use, and subnets can now by up to 64-bits in length – which really just means there is far more space for different masks.
So, if this is so great and needed so badly, why don’t we have it? Why hasn’t IPv6 been implemented by now? Well that’s a hard question to answer really. A lot of it is just what our infrastructure is designed for, which is IPv4. It will be expensive and difficult to update everything to a new system, and ISPs have to allocate new blocks of addresses and update all their users, routers and devices. Some hardware manufacturers already place IPv6 addresses in their devices. Apple for instance was one of the first to take a portion of IPv6 and all computers and routers bought from them have IPv6 installed. The long and short of it is that it will take time and money to drastically change our internet for the entire world. But it must happen. Address exhaustion is kind of like a networker’s 2012 – it will be a huge mess to deal with and will stall growth. And yet the longer we wait to really be proactive about an update, the worse and closer to the brink we get. Changing to IPv6 will require real initiative from ISPs, governments and even citizens. It will affect all of us in unknown ways.
Well world, it’s January 2010. You’ve go until December 2011. Get to it.