The impending doom of the internet for dummies

The topic of the internet running out of IP addresses pops up occasionally on the web, much like other doomsday scenarios, such as the "OMG the LHC is going to destroy the Earth" and "Oh noes, this huge asteroid is coming right at us." Except, the limitations of the current internet standard are real, and the limited amount of IP addresses can pose real problems. And no, private networks and NAT are not a solution to those problems, and neither is IPv6, the newer version, being implemented fast enough to present an easy way out.

The Internet Protocol version 4, or IPv4 for short, is a protocol governing transmission of data packets between connected computers. Those data packets carry, bit by bit, your favorite websites, streaming video, torrents -- all the traffic on the web. Computers "recognize" each other by their IP addresses, and in order for information to be transmitted, each computer needs a unique IP address. An IPv4-defined address consists of four groups of numbers, from 0 to 255, separated by dots. An IP to remember, as an example: 127.0.0.1 is hardcoded into each computers as its own, "localhost" address. This arrangement limits the number of available addresses to 4,294,967,296 unique combinations (the address space), and those among you who are paying attention will have noticed that there are more people on the planet than this number.

Some hosting companies, particularly those in the US and Western Europe, have reserved for themselves large blocks of IP addresses, which effectively solves the issue for them and their clients. Governments and businesses in developing countries are not so lucky.

The limited number of IPs does not mean that there can exist only four billion web sites at a given time. The World Wide Web uses the Domain Name System (DNS), which allows different URLs to resolve to a single IP. Thus, hundreds of websites can be served from a single server, using one IP. But ideally, you would like your own IP for your website, so that you have full control over its operation. Furthermore, the envisioned connection of millions of modern mobile devices and other appliances directly to the internet will be impossible with a limited address space. This is the issue here: the internet is spilling out of PCs and laptops into a wide variety of devices, from IP-enabled phones to the proverbial IP-enabled toasters. In the same time, you would like to keep that unique IP your ISP gave you.

A widely adopted way to deal with the shortage of IP addresses is to use NAT and network masquerading. This allows for networks of computers to effectively share a single IP as an "entry point" to the wider network. But there are two big issues with that: accountability and functionality. Rarely there are complete records for the activity on every private LAN, and the added level of complexity is not an elegant solution, when you scale that up to thousands of users. Users won't get access to some protocols, router hardware will fail, you get the picture.

The ultimate solution is the implementation of IPv6, a relatively new standard, which by now is enabled in all modern operating systems. IPv6 was created in 1996, fifteen years after IPv4 was standardized. By the middle of the 1990s, people were beginning to realize that the global network needed more addresses. IPv6 address space is much larger -- so mindbogglingly large, in fact, that no further upgrades are required in the foreseeable future, even when individual companies start to assign IPs to all their products and services. Cool fact: there are taxis in Japan using their unique IPv6 address to receive traffic and weather information from the net.

Sounds good? Well, latest reports show that adoption of the new protocol is slow. And the IPv4 addresses are running out of stock, fast. In the final analysis, countries won't go to war over IP address spaces, but a congested system with an outdated design won't help the internet of the future, either.