Re: standards for giving out blocks of IP addresses
On Sat, 16 Jun 2001, David R Huberman wrote:
Either you're saying it wrong (writing it wrong, as it were) or you are misunderstanding RFC2050.
ISPs *should* request 80% utilization of a block assigned to an end-user prior to assigning additional address space.
You understand that, right?
On Sat, 16 Jun 2001 up@3.am wrote:
It's not really a question of what makes sense, it's what you need to do to keep ARIN happy. As an ISP, if you only apply the 25% / 50% rule to your customers, how are you supposed to demonstrate 80% utilization to ARIN when requesting any kind of allocation?
If you've handed out a whole bunch of /24 - /29 subnets to your customers and they are compliant with RFC2050, this could well result in a situation where you've depleted nearly all of your address space, yet are nowhere near 80% utilization or your, say, /21 from your upstream. Is ARIN going to allocate you a /20?
David: Sorry, but nope, I don't understand it that way. Perhaps we need to properly define utilization. To an ISP, this means assignment of address space via SWIP to customers. ARIN wants you to have "assigned" 80% of your address space before asking for another allocation. To an end user, it means active hosts. ARIN suggests following RFC2050 and the 25%/50% standard prior to receiving an additional address assignment from their ISP. You, the ISP, are obligated to have justification using RFC2050 as the standard for assignements to your customers. ARIN requires you to have assigned 80% of your allocation to those customers prior to receiving additional allocations and may want to review the justification you've received from your customers. So, yes, it's very likely that when you have assigned 80% of your allocation, the sum of all your customer's utilization may be something like 50%. Judging from the confusion on this issue, I'm not surprised that some customers have a hard time getting assignments from their ISP's. This is even more confusing when the customer is both an end user and a downstream ISP themselves. In that case, it may make sence to consider the address space they use themselves as a separate assignment from them to themselves. That way you can properly determine when they have reached 80% assgnment of their space. If they aren't in turn assigning address space, then they are simply an end user and should be following RFC2050. Does this all make sence? Chuck
Sorry, but nope, I don't understand it that way. Perhaps we need to properly define utilization.
For the purposes of the RIRs and for any ISP assigning or allocating address space downstream, 'utilization' refers to an appropriate assignment made. If I have properly assigned 80% of an address block to my customers, I am 80% 'utilized' for the purposes of the RIRs. It is entirely irrelevant how much address space is actually being used, on an IP x IP basis by downstreams. If the assignments were justified per RFC2050, and the upstream has assigned 80% or more of its available address space, then it requires another block.
To an end user, it means active hosts. ARIN suggests following RFC2050 and the 25%/50% standard prior to receiving an additional address assignment from their ISP.
Please stop saying that. ARIN requires ISPs to follow RFC2050's guidelines for *initial* assignments to end-users. End-users must demonstrate a need for 25% of the requested assignment immediately, and a need for 50% of the requested assignment within one year. For *additional* address assignments from an ISP, an end-user should demonstrate that they have utilized (in this case, meaning active utilization in a 'live' sense) 80% of the initial assignment. The difference is an important one. 25-50 is for *initial*, 80 is for *additional*.
This is even more confusing when the customer is both an end user and a downstream ISP themselves. If they aren't in turn assigning address space, then they are simply an end user and should be following RFC2050.
The RIRs use the words "ISP" and "end-user" slightly differently than other folks. Any organization which does not assign their address space further downstream is considered an "end-user". It doesn't matter what their business activities are (indeed, they may be a service provider). For the purposes of this discussion, for the purposes of the RIRs, they are an end-user. /david
Let me respond to Chuck with an example, just for clarity's sake: EXXON, the gas folks, come to you and request a /20. They are using this /20 internally (say, to assign IP addresses to individual gas pumps across the US). They demonstrate to you that they are going to number 1,024 pumps upon the receipt of this /20. They demonstrate to you that they plan to number 2,048 pumps total over the next 12 months. A few months go by, and EXXON comes to you and says that they have number 3,400 pumps, and are now over 80% utilized on the initial /20 you assigned them. You can now assign them additional address space. You are not really justified to assign more address space to them until they have assigned 80% of their /20. (There are real-world examples where orgs need to request additional address space at the same time as achieving 80%, but let's not let reality get in the way of textbook examples!) The size of the additional block you assign them should closely fit the 25%-50% requirement. (Again, real world examples tend to trend to fitting the 50% requirement more than the 25% requirement, but so be it.) /david
On Sat, 16 Jun 2001, David R Huberman wrote:
You are not really justified to assign more address space to them until they have assigned 80% of their /20. (There are real-world examples where orgs need to request additional address space at the same time as achieving 80%, but let's not let reality get in the way of textbook examples!)
The size of the additional block you assign them should closely fit the 25%-50% requirement. (Again, real world examples tend to trend to fitting the 50% requirement more than the 25% requirement, but so be it.)
David: I think my prior response answers most of this, but it should be clear that the 25%-50% "suggestion" can't be compatible with the 80% requirement. These must be refering to two totally different things, particlulary because the 50% referes to a year, and RFC2050 suggests 3 month worth of IP address for subsequent allocations. Chuck
On Sat, 16 Jun 2001, David R Huberman wrote:
Sorry, but nope, I don't understand it that way. Perhaps we need to properly define utilization.
For the purposes of the RIRs and for any ISP assigning or allocating address space downstream, 'utilization' refers to an appropriate assignment made. If I have properly assigned 80% of an address block to my customers, I am 80% 'utilized' for the purposes of the RIRs.
Agreed.
It is entirely irrelevant how much address space is actually being used, on an IP x IP basis by downstreams. If the assignments were justified per RFC2050, and the upstream has assigned 80% or more of its available address space, then it requires another block.
Agreed.
To an end user, it means active hosts. ARIN suggests following RFC2050 and the 25%/50% standard prior to receiving an additional address assignment from their ISP.
Please stop saying that.
ARIN requires ISPs to follow RFC2050's guidelines for *initial* assignments to end-users. End-users must demonstrate a need for 25% of the requested assignment immediately, and a need for 50% of the requested assignment within one year.
Section 3 of RFC2050 refers only to the assignment of IP address space to end users. Section 3.1, which is the only place where the 25%/50% guideline exists, does not make any mention of that as being for "initial assignment". One can only assume in reading that section that this guideline is intended to be used for any initial AND ongoing assignments to END USERS.
For *additional* address assignments from an ISP, an end-user should demonstrate that they have utilized (in this case, meaning active utilization in a 'live' sense) 80% of the initial assignment.
The difference is an important one. 25-50 is for *initial*, 80 is for *additional*.
Please show where this is suggested in RFC2050. The only place in RFC2050 where the 80% figure is used is in section 2.2, and then only in relation to the level of assignment by the ISP and only for the purpose of determining whether there should be an additional allocation to the ISP by the registry. Further, there is no 25%/50% utilization guideline for an initial allocation to an ISP. RFC2050 specifically states that "The parent registries are responsible for determining appropriate initial and subsequent allocations." but doesn't state what that would be other than to say it should provide enough such that the ISP won't need to make another request for 3 months. So, please stop saying that the "25-50 is for *initial*, 80 is for *additional*."
This is even more confusing when the customer is both an end user and a downstream ISP themselves. If they aren't in turn assigning address space, then they are simply an end user and should be following RFC2050.
The RIRs use the words "ISP" and "end-user" slightly differently than other folks.
Any organization which does not assign their address space further downstream is considered an "end-user". It doesn't matter what their business activities are (indeed, they may be a service provider). For the purposes of this discussion, for the purposes of the RIRs, they are an end-user.
They are an ISP if they SWIP address space to customers. They are an end user if they don't. If they are an ISP, they should comply with the 80% assignment reccomendation. If they are an end user, they should comply with the 25%/50% utilization reccomendation. I guess I can't say it any more clearly than that and I'll say it again that I think some ISP's make it unnecessarily difficult for customers to get additional address space. It's apparent to me that they unwhittingly do this to their customers because they get confused about what's allocation policy and what's assignment policy (as testified to by the path of this thread). Chuck
As I suspected, we're arguing over mis-communication brought about by poor phrasing. - End-users' address space determinations are based on 25-50. - ISPs' address space determinations are based on their three-month needs. - Both are judged to have used their existing assignment 'efficiently' if they have used 80% of it.
I guess I can't say it any more clearly than that and I'll say it again that I think some ISP's make it unnecessarily difficult for customers to get additional address space.
As Randy Bush likes to say, I'm glad my competitors make life so difficult for their customers. Come to Global Crossing. You won't have that problem. All customers receive address assignments/allocations sufficient to achieve their goals within the framework of the assignment policies proscribed in RFC 2050 and by the pertinent RIR. /david
On Sat, 16 Jun 2001, David R Huberman wrote:
As I suspected, we're arguing over mis-communication brought about by poor phrasing.
- End-users' address space determinations are based on 25-50.
Yep.
- ISPs' address space determinations are based on their three-month needs.
Yep.
- Both are judged to have used their existing assignment 'efficiently' if they have used 80% of it.
Nope. But I give up.
As Randy Bush likes to say, I'm glad my competitors make life so difficult for their customers.
Ain't that the truth. Chuck
- Both are judged to have used their existing assignment 'efficiently' if they have used 80% of it.
Nope. But I give up.
You can't request an additional assignment of address space until you have efficiently utilized your existing address space. Why "Nope."? Otherwise, how can your request for additional address space be deemed justified? "We can't give you more - you still have plenty left from your last assignment."
David: I didn't really want to continue this thread, but now we seem to be getting down to it. Unfortunately RFC2050 doesn't address at what point additional address space should be assigned to an end user, however, it never uses the 80% figure in that respect. It would seem then that if an end user has a current assignment and something changes in their business that would reasonably require more address space, and after the assignment of the additional address space they would have 25% immediate utilization and 50% within the year, then it would seem to be consistant with RFC2050 to assign them additional space. This means that if they are already at 50%, you assign them another block equial in size to what they have, and they reasonably expect to double their utilization in the next year, that everyone should be happy. I think you need to keep in mind that managing assignments to end users is infinately simpler than managing the distribution and implimentation of IP address space by the end user. I believe that is part of the reasoning behind the 25%-50% criteria. On a slightly different vein, how you do measure utilization by the end user? Is it by actual hosts active + broadcast addresses for all net/subnets, or is a subnet that has a reasonable number of hosts and space for expansion considered fully against the 25%-50% criteria? I suppose that's a discussion for another day, but is yet another area where ISP's/end-users have a tendancy to clash. Chuck On Sat, 16 Jun 2001, David R Huberman wrote:
- Both are judged to have used their existing assignment 'efficiently' if they have used 80% of it.
Nope. But I give up.
You can't request an additional assignment of address space until you have efficiently utilized your existing address space. Why "Nope."?
Otherwise, how can your request for additional address space be deemed justified? "We can't give you more - you still have plenty left from your last assignment."
--
Since this is NANOG, I'll restrict my comments to ARIN policy:
Unfortunately RFC2050 doesn't address at what point additional address space should be assigned to an end user, however, it never uses the 80% figure in that respect.
Interestingly, ARIN doesn't publish any policy on additional address space assignments to end-users. However, I can tell you that in practice (and it's common sense, too) ARIN does not issue additional assignments to end-users until they demonstrate that they have used their previous assignment efficiently (80%). Why? Because:
This means that if they are already at 50%, you assign them another block equial in size to what they have, and they reasonably expect to double their utilization in the next year, that everyone should be happy.
You can't use 25% of the additional block immediately if you still have 50% of the initial block available*. Again, though it's not written down (Richard Jimmerson?? Comments?), ARIN does not issue end-users additional blocks until their existing blocks are efficiently utilized. /david [*] if you can, you're a special case that's not material to this discussion.
Again, though it's not written down (Richard Jimmerson?? Comments?), ARIN does not issue end-users additional blocks until their existing blocks are efficiently utilized.
ARIN does review requests for IP address space from end-users who can justify the minimum assignment size of a /20, as described at http://www.arin.net/regserv/ip-assignment.html It is true that end-user organizations who request additional IP address space directly form ARIN must demonstrate 80 percent of their prior assignment has been efficiently utilized before their new request may be considered. It is also true this is not stated at the above referenced URL. It is stated at a different URL where ISP guidelines for issuing additional IP address space to customers is described (more about this below). A discussion about adding this language to http://www.arin.net/regserv/ip-assignment.html will take place on ARIN's public policy mailing list (ppml@arin.net). ARIN's policy mailing lists are open to everyone. Subscription information and archives can be found at http://www.arin.net/members/mailing.htm When it comes to ISPs who assign IP address space to their end-user customers, it is expected the assignment size will be determined based on the customer's 25 percent immediate and 50 percent one-year needs, as described in RFC 2050. It is also stated at http://www.arin.net/regserv/addipspace.html that ISPs need to adhere to the following when considering requests for additional IP address from their customers: "Reassignment information for prior allocations must show that each customer meets the 80% utilization criteria and must be available via SWIP/RWHOIS prior to your issuing them additional space." Richard Jimmerson Director of Operations American Registry for Internet Numbers (ARIN)
-----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of David R Huberman Sent: Saturday, June 16, 2001 7:23 PM To: Charles Scott Cc: nanog@merit.edu Subject: Re: standards for giving out blocks of IP addresses
Since this is NANOG, I'll restrict my comments to ARIN policy:
Unfortunately RFC2050 doesn't address at what point additional address space should be assigned to an end user, however, it never uses the 80% figure in that respect.
Interestingly, ARIN doesn't publish any policy on additional address space assignments to end-users.
However, I can tell you that in practice (and it's common sense, too) ARIN does not issue additional assignments to end-users until they demonstrate that they have used their previous assignment efficiently (80%). Why?
Because:
This means that if they are already at 50%, you assign them another block equial in size to what they have, and they reasonably expect to double their utilization in the next year, that everyone should be happy.
You can't use 25% of the additional block immediately if you still have 50% of the initial block available*.
Again, though it's not written down (Richard Jimmerson?? Comments?), ARIN does not issue end-users additional blocks until their existing blocks are efficiently utilized.
/david
[*] if you can, you're a special case that's not material to this discussion.
Richard: I'm glad you jumped in here to clarify things from ARIN's perspective. Regardless of what the actual policy is, I think it's important for everyone to have a reasonable expectation that it's understandable and consistant. This is particularly true when end-users are involved. If you don't mind, I'd like you to further clarify a couple points below. Chuck Scott On Mon, 18 Jun 2001, Richard Jimmerson wrote:
It is true that end-user organizations who request additional IP address space directly form ARIN must demonstrate 80 percent of their prior assignment has been efficiently utilized before their new request may be considered. It is also true this is not stated at the above referenced URL. It is stated at a different URL where ISP guidelines for issuing additional IP address space to customers is described (more about this below). A discussion about adding this language to http://www.arin.net/regserv/ip-assignment.html will take place on ARIN's public policy mailing list (ppml@arin.net).
While my focus in this discussion wasn't on allocation by ARIN directly to end users, I'm glad to hear this discussion will be taking place.
When it comes to ISPs who assign IP address space to their end-user customers, it is expected the assignment size will be determined based on the customer's 25 percent immediate and 50 percent one-year needs, as described in RFC 2050. It is also stated at http://www.arin.net/regserv/addipspace.html that ISPs need to adhere to the following when considering requests for additional IP address from their customers:
"Reassignment information for prior allocations must show that each customer meets the 80% utilization criteria and must be available via SWIP/RWHOIS prior to your issuing them additional space."
The very next bullet point after the above quote is "Customers must follow ARIN guidelines for ISPs." I can see how those two bullet points are appropriate when those customers in turn assign address space to their customers, however, it seems funny to say that true end-users should be following guidelines for ISP's. This brings up a question I have hesitated to bring into the mix. What is meant by "80% utilzation"? It would seem to me that to apply this fairly and evenly to ISP's and end-users alike, that it needs to be a consistant definition. From that, I'd expect the definition to be 80% of the end-user's address space is internally assigned to specific tasks (sub-nets, ...) rather than simply defining it as 80% of the address space is in use by hosts (broadcast addresses, ...). In other words, if an end user internally assigns a block of addresses to an application where they expect that application to immediatly consume 25% of that block and 50% in a year, then that whole block should be considered consumed when figuring the 80% utilization target. Perhaps this is the common interpretation, but I suspect some ISP's don't figure it that way. In any case, if that's how ARIN intends the consumption of end-user space to be figured, then I agree that the 80% target for additional assignments to end-users is a rational figure. It would, however, be nice if that is stated in official policy so assignments are handled in a consistant manner. Chuck
participants (3)
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Charles Scott -
David R Huberman -
Richard Jimmerson