Addressing IPv6

Currently the majority of the world’s Internet runs on IPv4 (Internet Protocol version 4). If you wanted to roll out broadband to a majority of homes in the USA, Australia, or indeed any country today – you couldn’t do it on IPv4. There just aren’t enough addresses to go around.

An IP address (usually just called a network address) is a bit like a phone number on a telephone network. In order to connect to the phone network you need a phone number. In order to connect to the Internet, you need a network address.

Every packet of data that moves between computers contains the network address that it is going to, and the network address that it is coming from. If you’re downloading or uploading files, browsing the Web, sending email, or anything else, there’s dozens, hundreds or thousands of little packets of data being sent back and forth between the two ends.

Some carry the data, and some contain messages to indicate that packets have successfully arrived or occasionally that they have gone missing and need to be sent again.

Back in the 1990s, a new version of the Internet Protocol was developed: IPv6 (there wasn’t really a version 5, or at least not for very long).

Eventually, people knew, the pool of available IPv4 addresses would run out. There are 4294.97 million possible IPv4 addresses, but some blocks are reserved for special uses. In practice, there are only 3706.65 usable addresses 3706.65 million usable addresses that can be allocated to things like Web-servers, home computers, mobile devices and so on. That’s not enough for every home and business to have one, let alone every computer or mobile device.

A large corporation can use hundreds (a few use tens of thousands) to make their systems go. Some addresses get wasted, because it’s easier to allocate certain-sized blocks of addresses rather than the exact number required. Like blocks of phone numbers allocated to a PBX, the excess unused numbers in the block can’t really be used elsewhere.

You might remember the last time the phone companies in your country added an extra digit or two to all the phone numbers. You may not. They were able to do that by just upgrading each telephone exchange.

It isn’t that easy in Internet networking, because every device with an IP address is technically an exchange of sorts. You can’t just lump in an extra number without upgrading everyone at once.

So a new version of IP was required that could initially ride alongside IPv4. Oh, lots of other gimmicks and tricks have been tried to extend the amount of time before IPv4 addresses ran dry, but they’ve all pretty much been tried. It is estimated that the last allocatable IPv4 addresses will have been allocated between June and September next year – unless people rush to claim some extra before they run out. You know they probably will.

A few countries will have some blocks of addresses left until early 2012, but they can’t practically be assigned to regions other than that which they’re in, for technical reasons.

IPv6 (which every 4G mobile device already has, along with Windows XP and later, Linux and Mac OSX Panther 10.3 and later) vastly increases the number of available addresses from the 4.2 billion to 340 trillion trillion trillion addresses. That’s not a typo. That’s 34 and 37 zeroes. It’s roughly enough for one network address for every atom in the solar system. Like IPv4 not every address is available for general use, but we’re not likely to run out in a hurry. The whole IPv4 Internet becomes a small corner of the total IPv6 address space.

An IPv4 address looks like 192.168.77.254. An IPv6 address looks something like 2001:c50:809f:7:66be::7707:53. Thankfully, as always, we’ll mostly be working in site names and Web addresses and leaving computers to deal with remembering the numbers for us.

Many of the things we learned about IPv4 have been incorporated into IPv6. Certain things like connection security, and autoconfiguration. Plug your IPv6 device into a properly configured network, and there’s no more messing about to do. It just works.

If the network admin prefers that only authorized devices can connect, that can be handled as well. IPv6 can talk to IPv4 networks, but it is not very practical to go the other way except in the most limited fashions.

What they don’t generally mention in the media coverage is that IPv6 is fast. Under identical conditions, there’s a noticeable improvement in performance. Whether the protocol is more efficient, or whether it’s just that the software that handles it is better designed and implemented, I can’t tell you. It’s faster in all my tests, and that’s what matters to me.

Right now, hardly anyone is using IPv6. Less than one percent of things connected to the Internet. Why change? There’s not many sites out there you can’t get to with IPv4 (though there’s some).

doit-doomsday-clock But the clock is ticking.

Until we run out, few people want to be bothered getting their nice little networks set up to run IPv6. Once we run out, the disruption from not doing so will become increasingly severe.

I suspect we are actually beyond a reasonable time frame where there won’t be some disruption. Now it’s more a question of how much.” — David Conrad, the general manager of the IANA

Your Web-browser already understands IPv6 in most cases. Your email reader as well. About half your network-using software probably does. What about the other half? Do you even know what software won’t be able to talk to things after the changeover? Probably not.

There’s probably a heap of things on my system that will not be able to talk on the new parts of the Internet. I know Second Life doesn’t support it. Last I looked City of Heroes didn’t either.

Has your provider set up to give you the new addresses? Probably not. As IPv4 addresses began to get scarcer near the end of the 20th century, their value increased, along with the fees that hosting services and ISPs charged to allocate them.

In IPv6 there’s no scarcity. Everyone on the planet can have 32 times the size of the current Internet address pool for personal use without causing a dent. Scarcity has value and it is likely that your ISPs and hosting providers will hold out for every last dollar on the fees.

My network at home has been running IPv6 for a little over a decade now. IPv6 will happily run alongside IPv4 on the same systems.

We’re probably about as prepared as we can be. Setup is pretty easy (certainly simpler than setting up a traditional IPv4 network) and everything works – that we know of.

With potentially only 11 months to go before IPv4 addresses are exhausted however, we still expect our ISP to take 12-18 months to be ready.

How ready are you?



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