80% rule, based on feedback from the NCC RS department
Hi APWG, one of the issues pointed out by Alex le Heugh from the RIPE NCC RS department at the last RIPE meeting was the "80% rule" for additional IPv4 allocations, which has multiple, contradictory definitions in the current address policy documents. See here: http://www.ripe.net/ripe/meetings/ripe-59/presentations/leheux-rough-edges-o... on page 17-21 and http://www.ripe.net/ripe/docs/ripe-484.html, section 5.3 and 5.4 The different sections of the policy text both describe the rule slightly differently. This makes it unclear how the 80% rule should be applied. Let me explain by example: - a LIR has a /16, which is at 95% utilization, and a /19 that is at 40% utilization. Over all their address space, the utilization would be 88%. - interpretation 1: "if a LIR holds multiple allocations, every *single* of them needs to be filled by 80%" would result in "the LIR will not get a new allocation, because the /19 is only at 40%" - interpretation 2: "if a LIR holds multiple allocations, the grand total of them needs to be filled by 80%" would result in "the LIR *will* get another allocation, because they have used 88%". Personally, I think that the interpretation according to 5.3 of the IPv4 address policy document ("interpretation 2") is the intention of the policy. 5.4 (sub-allocations) was added later, and has language about the 80% criteria that is misleading - this section is only concerned about sub-allocations, and "the 80% sentence" was put in there to emphasize the existing rule, not to change it (I know that from the proposer of this policy change...). Now, "just changing the text according to what the WG chair thinks" would not be the right thing - so what I think is the way forward now is to get feedback from *you*, and if there is clear guidance from the working group on resolving this ambiguity, we run a formal proposal to change the wording of the document in one way or the other. (Please don't get into sidetrack discussions on whether "80%" or "IPv4" is useful, but focus on this specific question.) thanks, and regards, Gert Doering, APWG Chair -- Total number of prefixes smaller than registry allocations: 144438 SpaceNet AG Vorstand: Sebastian v. Bomhard Joseph-Dollinger-Bogen 14 Aufsichtsratsvors.: A. Grundner-Culemann D-80807 Muenchen HRB: 136055 (AG Muenchen) Tel: +49 (89) 32356-444 USt-IdNr.: DE813185279
On 26/02/2010 14:28, Gert Doering wrote:
Now, "just changing the text according to what the WG chair thinks" would not be the right thing - so what I think is the way forward now is to get feedback from *you*, and if there is clear guidance from the working group on resolving this ambiguity, we run a formal proposal to change the wording of the document in one way or the other.
(Please don't get into sidetrack discussions on whether "80%" or "IPv4" is useful, but focus on this specific question.)
From what I remember (and I'm open to correction here), RIPE currently uses interpretation #1. I.e. all allocations must be at least 80% full before
(tl;dr contingent: you can safely scroll to the exec summary at the bottom). Rather than look at the immediate issue of which 80% rule trumps which, it may be instructive to be slightly naughty and examine how the allocation top-up mechanism works in practice. the LIR is entitled to request more address space. The net effect of this policy is that where it's applied, the overall LIR utilisation will have a lower bound of 80%, but will generally be higher than 80% overall. If we move to interpretation #2, we're lowering the bound to exactly 80%. There are 6145 LIRs with ipv4 allocations defined in the following file: ftp://ftp.ripe.net/pub/stats/ripencc/membership/alloclist.txt If you'll excuse me for being sufficiently rude to post code, the top 50 LIRs have been allocated 236595200 ipv4 addresses (about 14 /8s) out of a total allocation space of 474883072 allocated addresses (about 28 /8s). So that's a little less than 0.8% of the LIRs holding 50% of the address space. For the purposes of this argument, I am ignoring the fact that most of the larger service providers around Europe operate multiple LIRs, so the number of addresses allocated to the largest 50 ipv4 address space holders in Europe will probably well exceed 50%. Now, these LIRs are entitled to request more address space when all their allocations are 80% utilised. Taking the top 50 LIRs, this means that under the current utilisation policy, there is fully legitimate slack space of 47319040 addresses, or almost 3 x /8s. Which brings us back to the 80% policy. I have two observations about it: 1. changing the policy to interpretation #2 will probably increase the slack space by a small percentage, and taking only the top 50 LIRs into account, this will work out to be a large number of addresses. 2. the slack ipv4 address space allocations held by the large LIRs already represents a very large amount of address space indeed. I contend that there is a legitimate argument to say that when the RIPE NCC runs out of virgin IANA ipv4 space to allocate, the slack space held by the tiny number of larger LIRs will effectively be allocated to them to the very significant disadvantage of the much larger number of smaller LIRs. Put another way, the 80% rule is fine for smaller LIRs, but is very biassed in favour of larger LIRs. If we're thinking about looking at how the 80% rule is applied, it may be appropriate to take the opportunity to creating either a minimum utilisation curve which starts out at 80% and increases monotonically towards something significantly larger, or else a step / gradient system which starts out at 80% for the first /x chunk of address space, 85% for the next /y%, and so forth. Nick
On 26.02.2010 15:28:07 +0100, Gert Doering wrote:
Hi APWG,
one of the issues pointed out by Alex le Heugh from the RIPE NCC RS department at the last RIPE meeting was the "80% rule" for additional IPv4 allocations, which has multiple, contradictory definitions in the current address policy documents.
See here:
http://www.ripe.net/ripe/meetings/ripe-59/presentations/leheux-rough-edges-o...
on page 17-21
and http://www.ripe.net/ripe/docs/ripe-484.html, section 5.3 and 5.4
The different sections of the policy text both describe the rule slightly differently. This makes it unclear how the 80% rule should be applied. Let me explain by example:
- a LIR has a /16, which is at 95% utilization, and a /19 that is at 40% utilization. Over all their address space, the utilization would be 88%.
- interpretation 1: "if a LIR holds multiple allocations, every *single* of them needs to be filled by 80%" would result in "the LIR will not get a new allocation, because the /19 is only at 40%"
- interpretation 2: "if a LIR holds multiple allocations, the grand total of them needs to be filled by 80%" would result in "the LIR *will* get another allocation, because they have used 88%".
Personally, I think that the interpretation according to 5.3 of the IPv4 address policy document ("interpretation 2") is the intention of the policy.
I agree. It may be that some feel that we need to make the policy more strict but I strongly feel that the interpretation 2 is the correct interpretation of the current policy. I think interpretation 1 is stricter than it should be, according to the writing and to what LIR's may reasonably expect when they read the policy and judge whether it is suitable to make a request or not. Rgds Nina Bargisen TDC NET
On 07/04/10 11:18, Nina Hjorth Bargisen wrote:
- interpretation 1: "if a LIR holds multiple allocations, every *single* of them needs to be filled by 80%" would result in "the LIR will not get a new allocation, because the /19 is only at 40%"
- interpretation 2: "if a LIR holds multiple allocations, the grand total of them needs to be filled by 80%" would result in "the LIR *will* get another allocation, because they have used 88%". Personally, I think that the interpretation according to 5.3 of the IPv4 address policy document ("interpretation 2") is the intention of the policy. I agree. It may be that some feel that we need to make the policy more strict but I strongly feel that the interpretation 2 is the correct interpretation of the current policy. I think interpretation 1 is stricter than it should be, according to the writing and to what LIR's may reasonably expect when they read the policy and judge whether it is suitable to make a request or not.
I also agree. "... may receive an additional allocation when about eighty percent of all the address space currently allocated to it... " In this context "address space" is a mass noun (we say 'a /24 of address space') and it only seems sensible to interpret this as an aggregate. The presence of 'all' only reinforces this point. On the separate issue of what the policy should read (as opposed to 'how to interpret it'): The fact is rarely do larger LIRs operate as a single business unit or entity, and so there is greater internal complexity inside the organisation. While some may choose to operate a single large LIR and business structure others operate LIRs on a per-country or per-business unit basis. If we are talking about creating policies to provide address space on an equitable basis it doesn't seem relevant to consider 'one LIR' vs 'lots of LIRs'. In extremis, someone starting 100 LIRs to gain a commercial advantage is clearly not a desirable situation. Will
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seem relevant to consider 'one LIR' vs 'lots of LIRs'. In extremis, someone starting 100 LIRs to gain a commercial advantage is clearly not a desirable situation.
Also agree, but on this paragraph feel I must state that we don't have a good framework to my knowledge which allows multiple LIRs to be considered together for policy purposes (controlled by same entity or not) so have to accept that best we can do here is to apply on a per-LIR basis. Dave. - -- - ------------------------------------------------ David Freedman Group Network Engineering Claranet Limited http://www.clara.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAku8fbcACgkQtFWeqpgEZrJbtgCgyYKGrLxOTON1oQsflae6kk5g j08AnAhKy/bZwpzuWcTzZsPYJtKqoD87 =w9Ov -----END PGP SIGNATURE-----
On 7 Apr 2010, at 11:18, Nina Hjorth Bargisen wrote:
- interpretation 2: "if a LIR holds multiple allocations, the grand total of them needs to be filled by 80%" would result in "the LIR *will* get another allocation, because they have used 88%". Personally, I think that the interpretation according to 5.3 of the IPv4 address policy document ("interpretation 2") is the intention of the policy. I agree. It may be that some feel that we need to make the policy more strict but I strongly feel that the interpretation 2 is the correct interpretation of the current policy.
I agree with Gert and Nina. The total number of addresses allocated to an LIR "just feels" like a fairer yardstick than treating the organisation as a series of disconnected islands of addresses, for the purposes of this policy. Thanks Andy, uk.dev
participants (6)
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Andy Davidson -
David Freedman -
Gert Doering -
Nick Hilliard -
Nina Hjorth Bargisen -
Will Hargrave