Now the world ends.

^ no reason to remember that address, or any other. Jafo pointed up the absurdity of those who said "We'll never need more than...".

We always end up needing more.

No reason to remember that address?  How do you troubleshoot when DNS is down?

Anyway, what I'm pointing out is that "we'll always need more" is a fallacy.  There is such a thing as enough. 

You write it down and store it in a phone or other device. The thing is, I hate cluttering my desktop and my brain. Unfortunately "enough" led to IPv4.... here we go again....

IP addresses should just not be used; just get the IP from the DNS server. Trouble shooting should be done by your operating system anyways.

------------

I really wich MS would restructure its networking API so that it would be agnostic about the IP version. Then future switches would be easier as older apps would stiil work (taking one part of the steps of change overs out of the picture, as the OS would just need to be updated).

More will not be needed, unless we make nanites that need an IP address each or move to other planets and have FTL long distance communications between them, but those are possibilities that should not be ruled out.

And it is a power of 2, which for computer stuff is more effecient. That is why is so big. They could have done a 64 bit value but changing over is such a pain...

"Anyway, what I'm pointing out is that "we'll always need more" is a fallacy.  There is such a thing as enough. "

Let's just concede that it's NOT a 'fallacy' but an OPINION, and a flawed one.

Unless we're into ZPG,

....and stagnation.

Go ahead. Tell us exactly how many IP addresses we'll EVER need. Then we can just go to the point and say 'we have enough'

Can't do it? Then better to have overhead room than to come up short.

It's just like the Y2K thing.

^Correct. Also exactly what I wrote in the OP.

Any technology that looks remotely like what we have today will never fill IPv6.  Suppose each human being needs 1000 devices, each which need 10 addresses, the world population increases to 100 billion, and 99/100 addresses that are alocated go unused due to waste of one form or another.  That's still only 10^17, or just over 2^56 addresses.  This is still considerably less than 1% utilization of a 64-bit range.  Or, to put the absurdity another way, let's say we want IPv6 to last for the next one million years.  We could safely issue one trillion IP addreses (that's 10^12) per second in the intervening period without depleting it.  Alternately, a 64-bit option would only be able to handle an average of just under 600000 IP addresses issued per second over the next million years. 

Until we start handing out IP addresses to nano-bots, the idea of running into the limitations of even a 64-bit range is ludicrous.  Perhaps one day in the distant future this may be the case, but it will be devices that look and act nothing like the devices of today that run into these sort of limitations.  For this reason, I find it significantly more plausible that IPv6 will be obsoleted for unrelated technical reasons long before it even comes close to filling a 64-bit range.  Feel free to come back and tell me "I told you so" if we ever do get that far, but I sincerely doubt you will get the chance.

That said, I have nothing against over-engineering in and of itself; it's not like it's difficult to do, and the comedy of the sheer scale of the address space is well worth it as far as I'm concerned

On the other side of the spectrum, I find it disgraceful how everyone has waited until IPv4 is actually depleted to make the transition.  This has been coming up for years, it's not like anyone in the field can claim surprise.

...Never need more than 640k.

Before that it was... Impossible to travel faster than sound.

Now it's... Won't ever use all the IPv6 address space in a million years.

What will be next?

Oh, right... Can't travel (as in physical transportation) faster than light.

Which will be proven false, first?

Even though I probably won't be alive to see it, I'd bet on IPv6.

I actually heard someone lecture on this quite a while back and also heard some press releases that there are those that have been working on it. I just don't know to what level.

But, I look at it this way: One of two things will happen. The net goes on happily beyond my lifetime and I am dead, thus don't care or it comes to an end within my lifetime and I survive much the same way I did before I started surfing the net.

Goodbye to you all if I don't get a chance to say so.

C'mon people, I accept that if we produce nanites on such a grand scale that we can fill the entire surface of the planet so that every part is obscured and stack them to unbelieveable height we *might* run someday out of IP addresses in IPv6. In that particular case it might be tho only hope for mankind to survive the onslaught of the nanites

Other than that, just, please, for the sake of your intellect, inform yourself, start calculating (not using a calculator, but your computer using a scientific program) and print the number of different IP addresses onto a paper. And then think about how you could in any meaningful way spend all those addresses in the lifetime this tech is probably to live (be it even a thousand years)

You'll be amazed how impossible this really is.

I'd be amazed. Nothing is impossible:

FAQ's about IPv6: http://www.isoc.org/internet/issues/ipv6_faq.shtml

http://gcn.com/articles/2010/08/02/update1-ipv4-dries-up-ipv6-on-deck.aspx

There are unused blocks in various hands (see prior replies) however, they are not yet for sale. IPv4 has 4 billion possible addresses. There are more people alive than that. IPv6 has 340 Undecillion addresses. Internet usage is exploding with computer and nobile device usage. Since there is a finite number of addresses, a larger supply had to be created: Hence, IPv6. You aren't require to believe it. It's fact.

My favorite is - "No one needs to run more than one program at a time!".

famous last words by one network engineer back in 94 - ME.

IPv6 has 340 undecillion potential addresses.  But that is divided up.  There are 18 quintillion networks each with 18 quintillion host addresses.  Beginning to see some of the waste?  That means every house has a potential for that many address that are different from every other house/business/office/organization/government.

Now 18 quintillion networks is MORE than enough for the planet today.  But not all of them are usable.  The IANA has reserved large blocks of addresses (like the old 10.x.x.x, 172.16.x.x-172.31.x.x, 169.254.x.x, 192.168.x.x, and 224.x.x.x-) for special purposes.  So there are not really 18 quintillion networks.  MIT just asked for - and was given, a /30 network address.  That gives them 17 BILLION networks all for their 5000 students.  Other universities are doing the same thing.

Also, when you connect 2 routers together, you have to assign the cable between them a unique network address.  Only 2 devices (hosts) will be on that network, but it does require a network all to itself.  So 18 quintillion addresses just got wasted.

That is the waste I am talking about.  And it will eventually cause the shortage of IPv6 addresses, even before we cover the planet with nannites.  But like IPv4, they will then start pulling some of the Networks back from the "fat boys" (like MIT), and they will go ahead and figure out how to make routers do greater than /64 subnetting for IPv6 so that there is no waste of 18 quintillion addresses just to hook 2 routers together..  The reason they have not done so from the outset is that the Internet Routers just are not capable of handling 18 quintillion routes, much less more than that NOW.  But they will be in 30 (or 40, 50 or more) years when it becomes necessary.