Friday, 26 June 2015

Do they not teach decimal numbers in school any more?

The ARIN IPv4 depletion web site shows how much IPv4 space is left for allocation in the American region.

It is a number of "/8s" left. For those that do not know, a /8 is 16,777,216 IPv4 addresses, and is the size of block allocated to each region at a time. The top level /8s ran out ages ago, and 4 of the 5 registries are no longer allocating IPv4 normally (most have policies on final allocations from remaining space). ARIN is down to the wire and shit will finally hit the fan any day now.

What I find most amusing is the explanation on that page, to explain a simple number, like 5.22 as apparently the meaning of "5.22" is not clear, well, not to Americans?

Of course, this explanation is fine, to explain a number like "5.22", and you can probably guess what the counter was when someone wrote that explanation. But reading it now, does that mean we have 0 /8s and 978% of another /8 left?

It is reminiscent of the 0.002 cent argument someone had with Verizon...

A NOTE ABOUT OUR /8 INVENTORY COUNTER

The counter shows the number of /8s remaining. The numbers after the decimal point are equivalent to a percentage (so 5.22 /8s is 5 /8s + 22% of a 6th /8).

18 comments:

  1. 164096 remaining IPs for ARIN. Surely that can't be more than a couple of months worth?

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    1. Wow, I'm actually kind of glad it's happening to ARIN first, as it's less likely to impact me than RIPE running out but with it including the US it will mean there are news stories etc about it. Maybe it will light a fire under certain UK ISPs etc.

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    2. Err, RIPE ran out of normal allocations ages ago. ARIN just have a different policy on their last /8. As an ISP you can no longer get allocations from RIPA (with exception of a /22 for new ISPs which is not that helpful).

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    3. http://www.potaroo.net/tools/ipv4/ has a nice list of run out dates. IANA ran out first (as they feed the five RIRs). Of the RIRs, APNIC ran out first, then RIPE, then LACNIC. ARIN is expected to run out any moment now, while AfriNIC expects to last until 2019.

      This excludes blocks reserved for post-exhaustion issuing; APNIC and RIPE both have a policy of one /22 per new LIR until they're completely out of addresses.

      ARIN, however, has chosen to keep allocating requested size blocks until they're completely out of addresses. This has the advantage that if you *need* a /16, and ARIN have one, you can get it; it has the disadvantage that it's possible for one big player to quickly and easily take the last remaining IPv4 space.

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    4. I'd be surprised if it lasts the weekend..

      ARIN are almost last to run out. Only AFRINIC left, so anyone not ready to deploy ipv6 by now is in for a bad time.

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    5. > As an ISP you can no longer get allocations from RIPA

      Is this a carefully-coded warning that you have RIPA on your mind for some reason?

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    6. LOL - no - a typo - we still have no black boxes, do not panic. Nice spot.

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  2. Surely if 5.22 is 5 whole /8s and 22% of another, then 0.00978 is 0.978% of the last /8, no?

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    1. In fact it ism, but the explanation they state is clear that "The numbers after the decimal point are equivalent to a percentage" meaning it is 00978% of another /8. That is the point of my post - why make an explanation of simple decimal numbers anyway, and then why have one that does not actually work for the numbers you are quoting (i.e. more than 2 places).

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    2. aah yes I see now. "equivalent to a percentage". that's craycray!

      so the reader has to take the number (00978 in this case) and divide by 100 to get the true value of the figure thereby leaving them with another damned decimal.

      so now we have 9.78 and the bit after the decimal is a percentage giving us 78/100 which leaves us with 0.78, and the bit after the decimal is a percentage giving us 78/100 and a curious case of déja vu all over again - so do we add this 0.78 with the previous 0.78 and get 1.56? (we've magicked a whole nother netblock now!)

      </troll>

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    3. Up until a few days ago the counter only had two decimal places.

      Shortly after it changed to 0.01 it was updated to five but the description wasn't updated.

      I suspect it's actually going to take quite a long time for ARIN to be completely exhausted (month or two) because there are still 400 odd /24s available and you can only make one request per three months. Also, anybody who wants a good place on the waiting list can't then take a smaller allocation from the available pool without being kicked off the waiting list for another three months.

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  3. Nice bit of causal racism against the poor old Americans there Rev. Never mind the Manhattan Project, the Apollo Project, the development of pretty much every protocol and electronic technology you ever use and the creation of enough wealth to fund the defence of Europe for the last 70 years or so.

    But they're probably still too stupid to understand decimal numbers. You reckon?



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    1. Hmm, well, yes, I was poking fun at them, but clearly the web site designer feels they have to explain what two digits after a decimal point actual means, and on more than one page even, so that does tell you something about their expected audience doesn't it? surely?

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    2. He/she might have been concerned that, in a discussion in the context of IP addresses, where a decimal point tends to indicate something completely different to its conventional meaning, there was room for confusion.

      Or perhaps he was clearing things up for the benefit of the women and blacks who might stumble across the page while looking for make-up tips and hip-hop info.

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    3. Hmm, whilst I may feel not too unhappy with a bit of a jape at Americans, I do not feel I would ever make that sort of comment.

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  4. I apparently bought .75 cl of wine in a restaurant this evening.

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