[ars]

There are a ton of /8 still assigned to companies that don't need them.

Ford, GE, IBM, AT&T (x2), Xerox, HP (x2), Apple, MIT, CSC, Eli Lilly, Nortel, Prudential Insurance, DuPont, Cap Debis, Merck, SITA.

All of those can return their /8. That's 18 /8 potentially available.

And does the DoD really need 12 /8's? I get that they want to network every person, gun, ship, tank, truck and plane. But none of those need to be on the public internet. (Well, maybe the people do - but 1 /8 should be enough for that.)

[Decade]

There are various reasons that the legacy IPv4 assignments are not returned. At the normal rate of IPv4 address assignment, circa 2011 when IANA ran out, reclaiming all those addresses would have delayed address space exhaustion by maybe 2 years at most.

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.

[Afforess]

Rumormill at IBM is that we bought some random companies a while back just for their IPv4 blocks. You didn't hear that from me though.

[jychang]

Doubt it, everything on IBM is natted to a 10.0.0.0/8 or is running externally to 9.0.0.0/8.

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

[peterkelly]

I think the suggestion was that they expected those blocks could become very valuable in the future and could thus be sold for a healthy profit. I don't think GP meant that IBM wanted to actually use those addresses themselves.

[recuter]

> All of those can return their /8. That's 18 /8 potentially available.

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.

[xxpor]

Right. How much code is out there that looks like

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

[sliverstorm]

I'm not sure if you are being sarcastic. I'd bet a lot.

[xxpor]

Not sarcastic. There's a ton of code like that. I've seen it.

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

[banachtarski]

I'm assuming that smiley face provides the missing paren.

[swixmix]

This could be a fortunate investment that will make them lots of money. Give it back? I doubt it. Sell it back? Profit.

[masklinn]

> This could be a fortunate investment that will make them lots of money.

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.

[davidw]

Apple is probably a bad example.

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.

[300bps]

owning a /8 can have invaluable uses

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?

[Dylan16807]

There's no reason they would have to return the entire thing. Some /16s would be fine.

[teddyh]

It would also be completely useless, as implementing the reassignment would dwarf the cost of moving to IPv6.

[michaelt]

Reassigning some ipv4 IPs on a handful of corporations' internal networks would dwarf the cost of upgrading the entire internet infrastructure to ipv6?

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.

[teddyh]

The entire internet infrastructure (backbone routers, etc.) is already using IPv6, so the cost of implementing IPv6 is, by now, entirely on the end-site side.

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.

[lmm]

>I get assigned a new ipv4 IP by DHCP every time I reboot my computer.

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.

[Dylan16807]

I think michaelt's argument was that it's easy to shuffle the IPs around inside the corporation to allow large, BGP-friendly blocks to be released.

[teddyh]

See, you'd like to think so. You'd like to think that there's an easy solution not involving you, because it would mean you don't have to do anything or learn anything new.

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!

[belorn]

In the global market, returning those addresses won't help at all.

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.

[mfincham]

Returning them would only delay the inevitable by a matter of months.

Deploy IPv6 today, it ain't hard.

[pyre]

How would end-user software deal with an IPv6 address though? Surely some of it is IPv6 capable already, but I would imagine that a lot of it makes assumptions about IPv4. If the OS were operating on a IPv6 network, would that software function correctly as long as the addresses were IPv4-compatible (i.e. within the IPv4 range, and not in IPv6 notation)?

[rdtsc]

They had enough time. This is not a new thing. Some ISPs were more proactive, some were not. Those invested man hours and hopefully they will reap the benefits while their competitors struggle.

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).

[pyre]

I'm mostly thinking about end-user applications that may just never get updated, though I can't come up with any off the top of my head.

[nknighthb]

Dual-stack, proxies, and (if absolutely necessary) actual tunnels can compensate for critical IPv4 apps. You can layer whatever you need to on top of IPv6.

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.

[sp332]

Dual-stack still requires an IPv4 address.

[mfincham]

"It depends", is unfortunately the answer. For very old software where it's not possible to patch it for IPv6 support (this is rarer than you might think!) then some kind of IPv4 NAT or a DNS64 style "application layer gateway" is required.

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.

[noselasd]

>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.

[pyre]

> Almost no software you're likely to be running is incompatible with IPv6

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

[justincormack]

Some people seem behind eg Twisted didn't have support look last time I looked.

[gizmo686]

You can run both at the same time. Any software that is not IPv6 compatible would still be able to connect through IPv4 and just not have access to IPv6 addresses.

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.

[gpvos]

We had some software that stored IP addresses in a field in a ':'-separated text line; luckily, the files were quite transient, so we could just change the separator into a semicolon and be done with it.

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.

[peterkelly]

Remember Y2K?

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

[masklinn]

> There are a ton of /8 still assigned to companies that don't need them.

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.

[300bps]

They are using 16,777,214 IP addresses? I think that's quite a stretch. 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.

[masklinn]

> They are using 16,777,214 IP addresses?

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.

[300bps]

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

I would ask you to please note that there are non-routeable addresses that can be used for these purposes. You do realize that the /8 they've been granted is a public Internet netblock? You realize that 99.999% of the world doesn't use public Internet addresses on their employee's workstations or internal servers?

But for the sake of argument let's assume Ford (one of the owners of a /8) has 200,000 employees and that each of them is using 10 public IP addresses. That's 2MM. Then let's assume they have 10,000 servers and each one is taking up 100 IP addresses. That's another 1MM for a total of $3MM which is less than 1/5 of the addresses they're currently allocated.

Oh, and Ford only has 164,000 employees and I guarantee that each employee isn't even using 1 public IP address let alone 10. And 10,000 servers with 100 public IP addresses is just as ridiculous. Do you see now how wasteful it is that certain organizations have these /8s?

Beyond that, it really sounds like you don't know the difference between a public and private IP address. If for no other reason, places like Ford should have been using private IP address space for internal servers and workstations for security purposes.

[ethomson]

No, it does not sound like the parent doesn't know the difference between public and private IP addresses.

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.

[300bps]

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.

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.

[wmf]

IBM is using 9/8. AT&T is one of the largest ISPs in the world. Hopefully any legacy space that isn't used will come up for sale soon.

[Negitivefrags]

Can those companies sell their IPs on the open market when the normal pool has run out? Is that allowed?

[lmm]

Legally it's an allocation, not ownership. The registry could simply revoke your allocations if it caught you selling them (though whether it would is another question).

[bifrost]

Exactly, its more like a lease. You can't actually sell an IP because you don't own them, but you are given a lease/license to use them.

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.

[300bps]

When I owned an ISP in 1996 I paid a larger ISP money to suballocate a range of a couple /24s to me. This happens all the time - look up any random netblock on arin.net.

[mfincham]

It depends on the policies of the RIR (Regional Internet Registry) in the region where the IPs are from.

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).

[duskwuff]

Many of the legacy allocations were made before RIRs existed, so no policies really apply.

[mfincham]

Sure, but when you want to update the WHOIS / reverse DNS or whatever you have to convince an RIR. If you don't care then I guess that's fine.

[wmf]

Yes, address blocks are being sold on a regular basis. The going rate is around $11/address.

[bifrost]

Short answer : no