[duskwuff]

> …short of reclaiming something drastic like the class A block 10 (you know, a really really bad idea), dang.

10/8 is off limits, but there are a bunch of /8 blocks which could likely be reclaimed if we really needed to, including:

- About half a dozen which were allocated to the US military in the early 1990s, most of which aren't even publicly advertised at all

- 44/8, reserved for amateur radio

- A number of other /8 blocks owned by corporations, which could potentially sell or return chunks of them if properly convinced

[X-Istence]

Even if a block is not publicly advertised, it is still entirely possible that it is used internally. Using the 10/8 range was not common place, and certain organisations have IP's that are technically publicly routable in their internal infrastructure.

As for 44/8, there are still those that use it, taking it away would mean having to renumber all of the equipment on that network...

No, trying to reclaim IPv4 addresses by making people go through herculean efforts to renumber their networks is not the way forward and simply delays the inevitable. IPv6 is the way forward, start pushing that, and get more people using it.

[slyall]

Claiming back /8s from companies won't work. 16 million addresses is just a drop in the bucket compared to growth in China, India and other countries.

It would take years to arrange the return of 100 million addresses compared to the demand for a few billion addresses with even conservative growth.

[xhrpost]

Yup, IANA was allocating two /8's per month before they ran out. At best, you'd get a few months of extra time. http://www.iana.org/assignments/ipv4-address-space/ipv4-addr...

[IgorPartola]

Obligatory: http://xkcd.com/195/

Edit: I wish there was an updated version.

[danielweber]

What is that way of ordering numbers called? If I knew the name I could google it but that's what I'm missing.

[Coincoin]

It's called a Hilbert Curve.

https://en.wikipedia.org/wiki/Hilbert_curve

[tbrownaw]

It's a variety of space-filling curve.

That's enough to find out that this particular one is called a Hilbert curve.

[Cameron_D]

http://internetcensus2012.bitbucket.org/images.html

This page has similar images from 2012

[carsonreinke]

Yeah, Ford definitely does not need its own block

[icedchai]

Who doesn't? I have my own /24 - registered back in the early 90's.

[rjsw]

Ford has as much reason as anyone else to need a block.

Consider subcontractors needing to connect to servers in a particular department.

[mikeash]

Ford has an entire /8, a significant chunk of the entire address space. Ford does not have as much reason to need that much address space compared to, say, major ISPs.

[rjsw]

I would argue that Ford (and the other multinationals) have more need of an /8 than any university that is just in a single city.

[hrrsn]

A /8 is 16,777,216 addresses.

Ford has 181,000 employees as of 2013 (http://en.wikipedia.org/wiki/Ford_Motor_Company).

That's very roughly 92 publicly routable IP addresses per employee.

I highly doubt they need that many.

[icefox]

What about 1 per car?

[mikeash]

I would agree, and say that universities with an entire /8 probably shouldn't have them anymore either. That's a case where it definitely made sense early on, but stopped making sense quite a while ago.

[justincormack]

Imperial College had two as the computer science department had its own /8. Probably still does.