All it would have cost was unpredictable, unbound man-years of work as each organization tracked down each of their publicly addressable machines, not all of which were recorded, and vacated into smaller subnets of their address space. I'm sure you know of the servers that sometimes disappear behind walls during renovations. And some of the older machines require the kernel to be recompiled and rebooted to change their IP address. Ah, those were the days.

We just have to face the fact that IPv4 was not designed to be used on a network the size of the Internet. NAT and CIDR have stretched it out amazingly, but we've stretched it out about as far as it will go. We need to switch to IPv6.

Source: I work at IBM, in a division that was another company that was bought out a few years back.

If say, Apple is using at least a little bit of that /8 here and there (safe assumption, no?) its going to be hard for them to return it. I'd wager corporations that have /8s have policies that rely on the assumption that they have the whole /8.

So I wouldn't hold my breath on getting one back from them.

     if(recv.ip.contains("2.") {
         //well we know that they're from X co.
     }

Also, I'm surprised no one called me out on the typo and bug in my code :)

Apple has ~$150b in cash reserves. Selling a /8 would amount to nothing on their balance sheets, whereas owning a /8 can have invaluable uses.

Presumably, as the good in question becomes scarcer, its value will increase to the point where it makes sense to sell it, or use alternative solutions.

When IPv6 is fully implemented, an IPv4 /8 will be essentially worthless. Reasonable people can disagree as to when that day will come, but it will come. It's probably not that far off.

Why not sell it or suballocate it while you can still get money for it?

I get assigned a new ipv4 IP by DHCP every time I reboot my computer. And you should hear the infrastructure people at my ISP and workplace and university squeal when you ask them about ipv6 - far too much work, they say, no plans on the horizon.

You should also include a number of additional cost of reassignment, including growth of routing table size.

I'm sorry to inform you that apparently your ISP, your workplace and your university are all either lazy, lying, or both. Implementing IPv6 takes, maybe, a few weeks if you have many servers and a large internal network. If all you have is a webserver which you want to be reachable by IPv6-only customers, an interim solution (tunnel) can be implemented in a few minutes.

Sure - from your router's subnet. The route to that address still goes to that router. There's no BGP update to propagate, no routing table entry to add to every router on the internet.

I mean, why not assign every IP address individually? That way we'd be fine for up to 2^32 internet-connected devices. Every router would just have to store all 2^32 routes in memory and send out a BGP message whenever anyone rebooted. Can't see any problem with that.

However, as pointed out in many other comments in this thread, this (and many other knee-jerk reaction "solutions") won't actually work, or would be significantly more expensive than implementing IPv6.

It's been on the horizon for nearly 20 years. It's coming soon now. The IPv4 end is nigh. Repent!

Currently, the only reason the American registry still has any IP addresses left, is because their pool was separated from the emerging markets in Asia. As such, if IANA would start extracting IP address as suggested, the global market would eat it up faster than IANA could collect them. It would only "work" if IANA gave all the addresses exclusively to the American pool, working towards a local Internet rather than global.

Deploy IPv6 today, it ain't hard.

Same with OS and software support.

In the end some will profit from this (even the lazy ones -- "quick, pay us for a new version that enables IPv6 support) and some will lose (they'll find competitors did a better job at IPv6 support).

Non-critical applications where people aren't willing to jump through any hoops... Well, it's not exactly news that sometimes old apps get left behind in technology transitions.

You could also potentially add a specific wrapper for your application e.g. wrapping MySQL connections inside of stunnel allows them to run over IPv6 in version of MySQL built with v6 support, or for simple daemons you can do things like set up socat to proxy between an IPv4 socket and an IPv6 socket.

Almost no software you're likely to be running is incompatible with IPv6, though. Software support for IPv6 is way ahead of actual network implementation.

How sure are you of this ?

Now, ofcourse all the major widely deployed software, be it browsers, web servers, mail servers and clients, remote file systems and similar are already IPv6 ready. What about all the many many millions of custom built systems and applications ? The kinds you will never see, that's hidden behind a corporate wall in use by 10-100 people.

Or all the devices that people have bought - all the wifi routers, IP cameras, network printers, DSL modems and so on ? It doesn't matter how much anyone says that these should have had time to support IPv6. If they arn't, it'll cost someone money to replace them - not all are willing to do that.

What about user inputs that only accept IPv4-formatted addresses? :P

The bigger issue would be connecting to IPv6 only servers from an IPv4 program. The first question is how many IPv4 only programs exist in the wild. If you happen to have one, and cannot update it, then you still have the option of creating an IPv4 to IPv6 proxy for the specific site(s) you need.

Elsewhere, the IP addresses were used as part of a file name on Windows; we replaced all colons in the IPv6 address with '!' to fix that.

There's bound to be lots of old software with similar problems around.

Sometimes software simply has to be upgraded to meet changing circumstances.

You've got no idea how they're structured internally. Some of those companies uses their blocks to make every machine in their network globally routable, they don't "need" them but they do use them and they're part of their network architecture.

No, they are using their block and their network strategy is predicated upon having an essentially infinite set of IP addresses available.

> I work at a company that has 19,000 employees with locations all over the world. We couldn't make a dent in 16.7MM routeable IP addresses.

Please note that not only can there be multiple IPs per employee, there are also IPs assigned to services and servers.

What it sounds like is that you expect Ford to take the time and energy to renumber their entire network just because they presumably don't need a /8. And while it's true that they probably don't need a whole /8, making them renumber is ridiculous.

So either you didn't read the original argument, or you just like to argue so you are now changing the argument. In either case, I'll bite.

Nobody is asking Ford to be altruistic about this. Right now their /8 has some value. They have a lot of options, not the least of which is to suballocate it for a tremendous amount of money. That's a given - they could probably also come to an arrangement with IANA/ARIN to just sell a part of it back. They'd make a tidy sum in any case. The alternative is the status quo. In 10 years their /8 will go from being worth a lot of money to being worthless. After all, what value would 16.7MM addresses have after IPv6 is fully implemented with its 2^128 addresses?

Companies renumber all the time. And let's be honest... how much renumbering would they really have to do? That whole fantasy land that "every employee must be using multiple public IP addresses" is just plain silly.

> > No, they are using their block and their network strategy is predicated upon having an essentially infinite set of IP addresses available.

> I just knew someone was going to totally change the argument. The argument I was replying to was that they use 16.7MM addresses. I proved that there is no way they use 16.7MM addresses.

No, the argument you were replying to was that they make use of the entire address space, which does not at all require every address to be in use. For example, each of their /16s may be used for a different organization, product, or location, and it's likely that many of the /24s for each /16 are further logically divided for organizational and routing purposes.

The idea the original claim was trying to disagree with was that all the network infrastructure in place was using a monolithic /8 with no logical divisions. Specifically, "them" in masklinn's comment was referring to "blocks", not addresses.

> Some of those companies uses their blocks to make every machine in their network globally routable, they don't "need" them but they do use them and they're part of their network architecture.

Some of those companies uses their blocks to make every machine in their network globally routable

Really? If you're anything resembling a network engineer, surely you see how ridiculous this is? And how about this other thing he said:

Please note that not only can there be multiple IPs per employee, there are also IPs assigned to services and servers.

Again, really? Multiple public IPs per employee? That's just poppycock. He was wrong, I called him out on it and you can try to re-interpret what he said all you like but the fact is he is just plain wrong. They're not using 16.7MM addresses, they're probably not even using 10% of 16.7MM addresses and assuming that every /8 holder broke their netblocks up in the least flexible and most wasteful way possible is nothing more than an assumption on your part.

You're right, I was being rather generous in my interpretation, and I don't actually know his intent.

Frankly, the only way to truly transfer an IP block between companies is to have one company buy the other, then the IP addresses can be reallocated to the new owner. You can't just transfer an IP block to another entity according to ARIN's registration agreement.

That said, if you're willing to ignore the RIR's policies (which a lot of people do) you can usually "black market" trade IP addresses, so long as you can convince your upstreams to accept them (which they usually will).