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Wednesday, October 15, 2008

Probe Sees Unused Internet

A survey shows that addresses are not running out as quickly as we'd thought.

By Robert Lemos

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Far and wide: This map was created using data from the researchers' census. About a quarter of the address space is still unassigned (blue), a quarter appears to be relatively densely populated (green), and nearly half of the space has few servers or did not respond to queries (red).
Credit: University of Southern California's Information Sciences Institute

In a little more than two years, the last Internet addresses will be assigned by the international group tasked with managing the 4.3 billion numbers. And yet, while most Internet engineers are looking to Internet Protocol version 6 (IPv6), the next-generation Internet addressing scheme, a research team has probed the entire Internet and found that the problem may not be as bad as many fear. The probe reveals millions of Internet addresses that have been allocated but remain unused.

In a paper to be presented later this month at the Proceedings of the ACM Internet Measurement Conference, a team of six researchers have documented what they claim is the first complete census of the Internet in more than two decades. They discovered a surprising number of unused addresses and conclude that plenty will still be lying idle when the last numbers are handed out in a few years' time. The problem, they say, is that some companies and institutions are using just a small fraction of the many million addresses they have been allocated.

"People are very concerned that the IPv4 address space is very close to being exhausted," says John Heidemann, a research associate professor in the department of computer science at the University of Southern California (USC) and the paper's lead author. "Our data suggests that maybe there are better things we should be doing in managing the IPv4 address space."

The census, carried out every quarter since 2003 but only recently published, is the first comprehensive map of the Internet since David Smallberg, then a computer-science student at the University of California, Los Angeles, canvassed the Internet's first servers--all 300-plus of them--following the switchover from the ARPANET in early 1983.

Internet Protocol version 4 (IPv4) addresses are typically managed as network blocks consisting of 256 addresses (known as a C block), 65,536 addresses (known as a B block), or approximately 16.8 million addresses (known as an A block). About a quarter of the A block addresses--the largest segments of the Internet--were given out in the first days of the Internet to early participants and to companies and organizations including Apple, IBM, and Xerox.

Today, A blocks are issued by an organization called the Internet Assigned Numbers Authority (IANA) to large Internet service providers or to regional registrars to which the A blocks are resold. But because accelerating use of the Internet is quickly eating up the remaining free blocks of network addresses, the last blocks will likely be given out between the end of 2010 and 2011.

The next-generation Internet address scheme, IPv6, solves the shortage by vastly increasing the number of addresses available. While IPv4 offers about 4.3 billion addresses for the earth's 6.7 billion people, IPv6 will offer 51 thousand trillion trillion per person. However, the move to IPv6 has progressed slowly because of cost and complexity, even with recent mandates for use of IPv6 within the U.S. government.

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Comments

  • FTC ought to do campaign like they are with DTV09
    Sjobeck on 10/15/2008 at 2:17 AM
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    The FTC ought to be doing a campaign exactly like they are with DTV 09.

    It is absurd that most ISP's dont even have any IPv6. We keep asking & asking here in PDX & next to none of them have any to give us.
    Rate this comment: 12345
  • IPv6
    zig158 on 10/15/2008 at 7:21 AM
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    Keep in mind that ipv6 headers are quite a bit larger, so the same amount of traffic will take more bandwidth. My point is that there are drawbacks to IPv6 that are rarely mentioned.
    Rate this comment: 12345
    • Re: IPv6
      trejrco on 10/15/2008 at 9:18 AM
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      I think they are quite frequently mentioned, but for the VAST majority of the Internet's users the extra 20B or so will have no negative impact ... especially when weighed against the benefits (first and foremost - the continued growth of the internet)

      /TJ
      Rate this comment: 12345
  • Address Exhaustion
    trejrco on 10/15/2008 at 9:26 AM
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    For those curious, the IPv4 address exhaustion date probably comes from something like this ... an excellent resource, and thanks to Geoff Huston for providing the site.

    Anyway, the actual date isn't the important thing - from a big picture perspective, that is. The real issue is - can IPv4 scale to our needs for the forthcoming years, decades, etc. Factoring in the increasingly connected world we live in, with the definition of "network enabled device" changing (cel phones, gaming consoles, automobiles, sensor nets, etc.) I think the resounding answer is no.

    So, do we spend lots of effort over the next 2 years prolonging IPv4 for 1-5 years beyond that, or do we "buy in" to the real answer and spend our time and effort primarily on that, while also working to ensure a semi-graceful period of coexistence?

    For the really motivated, get active! The IETF is working on these semi-graceful coexistence efforts now'ish, here
    Rate this comment: 12345
  • Re: Probe Sees Unused Internet
    rvandell on 10/15/2008 at 11:20 AM
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    Perhaps if the original class-A's used more VLSM on the outside, we could recover a bunch.

    How many class-A's does any one firm need publically is the question. "Too Much" is no longer the answer.
    Rate this comment: 12345
  • Old News
    billve on 10/15/2008 at 5:42 PM
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    I am very surprised that this is even being reported.  There have been in-depth conversations on the utilization percentage vs. allocation, as well as the merits and pitfalls of reclaiming "legacy" space, for several years now within ARIN and the other RIRs.  There have been a number of studies, using a number of different test methods.  This one is certainly not the first in many years -- it's another in a long line of studies that have been performed in the last 10 years.

    While it certainly makes sense to more widely publicize the issues surrounding IPv4 exhaustion and a conversion to IPv6, this article suggests that the answer has been staring us in the face all this time, and that everyone has been missing it.

    The reality is that legacy address space reclamation is an ongoing effort that has been underway for years, as have efforts to improve utilization.  The fact is that this study minimizes the blindness of its survey method and utterly ignores the fact that all the reclamation in the world will not do anything more than buy us another year or two, maybe less (as mentioned in another thread here).

    IPv6 is a near-term necessity.  IPv4 will not last much longer.  IPv6 is available in all major OSs and appliances.  There is no other alternative on the horizon.  It's time to get to work resolving the remaining technical issues, and move forward!
    Rate this comment: 12345
  • care about conclusions
    johnh on 10/16/2008 at 1:08 AM
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    (I am a co-author on the study that is described in this article.)

    The article provides a nice summary of the issues, but it reaches a conclusion that is stronger supported by the study. The subhead of the article is "A survey shows that addresses are not running out as quickly as we'd thought", and the article draws the conclusion: "the problem [of IPv4 address exhaustion] may not be as bad as many fear."

    The article's conclusion, I think, overly simplifies matters---it is only true if the "better things we should be doing in managing the IPv4 address space" are free. The Internet Census we carried out supports the opportunity for better IPv4 address space management. But an open question is the cost of such management. Historically, with plentiful IPv4 addresses, IPv4 management costs have been small, but potential better IPv4 management will likely be much more costly. This cost of ongoing IPv4 management needs to be weighed against the costs of one-time conversion cost to IPv6 coupled followed lower IPv6 management costs.

    To me, one exciting conclusion from the Internet Census we carried out is that we now have data that allows us to start evaluating these trade-offs. The answer may be more careful IPv4 gets us a few years, or that the cost of more careful IPv4 makes IPv6 an obvious choice. In either case, resolving this transition is important for the Internet community.
    Rate this comment: 12345
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