Jeff, are IP addresses reaching a limit?

[URL=http://www.smh.com.au/technology/technology-news/less-than-a-year-until-internet-addresses-run-dry-20100726-10r83.html?autostart=1 ]This article [/URL] says they are.

What's your take?

David

Yes, we are running out of available publicly managed IP addresses (IP version 4, that is), and it is a real problem, but the article is a little sensationalistic on account of its limited technical detail.

As the article and accompanying video note, there are only 4,294,967,296 possible IPv4 addresses (actually a bit less than that, because some are for special uses and can't be assigned to an individual computer). But it is possible, and common, to work around that in certain cases. For example, the typical home network only has one public IP address--the one assigned by your Internet service provider--but it may actually use a number of private addresses inside the network via Network Address Translation which does not 'use up' any additional public addresses. (The internal network will likely use addresses in the range 127.<anything> or 192.168.<anything>, because these are special address ranges which are not forwarded through routers.) These same private addresses may be reused at the same time by many private networks, because these private networks never see each other directly, so there's no confusion between them. Your router handles forwarding traffic between your single public address and your possibly multiple private addresses.

As another example, you don't have to 'own' your assigned IP address all the time, because you're not using it all the time. An Internet service provider will have a pool of addresses allocated to it by the central address assigning group, and it can delegate an available address whenever you need it, and delegate it to someone else when you don't need it. That way, it can serve more customers than it actually has addresses for. Of course, that is only useful when customers are actually not online all the time, so that the addresses can be reassigned.

But of course, these techniques will only get us so far; eventually we will indeed run out of available public addresses. And that's what IP version 6 (IPv6) is supposed to fix for the foreseeable future. The way it fixes it is by making IP addresses four times as long, yielding something over 300,000,000,000,000,000,000,000,000,000,000,000,000 possible addresses. The problem, as the article notes, is that most of our software is still designed for the shorter IPv4 addresses, and doesn't know how to handle the longer IPv6 addresses. And since we're not in the crisis yet, and people are still making workarounds, the urgency for converting all our Internet-handling software to IPv6 has been limited. But it's getting there. And existing devices should still work the same as they ever have; they just won't be able to communicate with ones which have already made the switch--although again, there may be workarounds to postpone the complete upgrade, such as using IPv4 addresses within private networks, and IPv6 in the public network between them, with routers handling the translation at the network borders.
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Stephen

Good answer, Stephen. I have little to add in the way of facts. My impression is that this is a problem, like the year 2000 issue of a decade ago, which will be solved by others and will be invisible to the typical user.

The workarounds with local IP4 addresses and non-fixed addresses and port forwarding work well now. I don't see any reason why they won't continue to work for most people and most purposes for the next few years.

Plus all that has to be done is to raise the prices for a fixed IP4 address and you'll see many IP4 addresses suddenly becoming available. I see many businesses which are assigned a block of 10 IP4 addresses when they sign up for a business DSL account, for example, which use only one of them. Most don't even remember that they have more.

Jeff/CompGuy