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On Mon, Jan 19, 2004 at 10:22:08AM -0800, william@elan.net wrote:
Also as you know I have been running statistics at http://www.completewhois.com/statistics/ (note: dont believe about "green" for 70/8, I still have not fixed collection to ignore occasional single wrong announcements from routeviews)
Its interesting that 69/8 block is currently only 39% allocated. To be honest I was not expecting ARIN to request another block under such condition, I was expecting when its either almost full (say 75%) or when it reaches previously agreed upon mark of 50% (see my other post). The only thing I could think of is that ARIN is allocating smaller block leaving some portion of the block "in reserve" for future allocation to the same entity and as a result it reached "critical point" of beyond 50 percent point of the block. So I checked and found that 69.128.0.0/18 was actually allocated on 2003-03-25. Checking again, it turns out the last (in terms of beginning) allocation they have is 69.178.0.0/17 made on 2004-01-13. Ok so 0-178 makes it 70% used for that class-a as far as point they reached for allocations.
Yes, ARIN typically leaves at least 100% (or more depending on growth patterns) of the initial allocation as unallocated space, left in reserve for future growth. If the user comes back for more IP space, they just expand into that unallocated space, without the need to create non-connected allocations which can't be aggregated. Eventually if you don't come back and claim your space, it is given away to someone else (btw I'd love to know the timelines for that). The 39% number makes a lot of sense given the 70% usage measured "in sequential order". I'm sure that the number of people who have come back for space is slightly higher than 4%, and is offset by some larger reservations (ex: the people who are on their 2nd or 3rd allocation, who have already been through a /19 or /18, and who are reserved a /16 even though they only eat new blocks a /19 at a time), but it's a good rough estimate. One point I would make is that ARIN certainly gives itself a luxury that its users do not have when it comes to reserving IP space for the future growth of its customers. The only option providers have to reserve space for their customers and still continue to get new IP space under the 80% utilization rules is to SWIP their customers a larger block than they need, and then explain it to ARIN when they ask how that customer justified said block (and there are still plenty of hostmasters who will argue with you about it :P). This is easier to do for end users because of their lower utilization requirements, but more of a pain for reallocations to people who will reallocate themselves. Also, it doesn't have quite the same effect for keeping customers in line when you hand them a SWIP for 2x what they asked for and say "try to use this efficiently, and keep the 2nd half reserved for your future growth" instead of being able to portion it out to them. I would rank this problem as one of the larger contributors to the /24 announcements on the global routing table, as customers with a steady growth pattern who don't want to pay ARIN a few thousand dollars for direct IP space keep coming back for space which their providers can't hold in reserve and still keep ARIN happy. -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)