standards for giving out blocks of IP addresses

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1

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

2

  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

3

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

4

> 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

5

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

6

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

7

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

8

> - 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."

9

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

10

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.

11

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)

12

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

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