[arin-ppml] Draft Policy 2009-2: Depleted IPv4 reserves

Owen DeLong owen at delong.com
Tue Mar 24 13:19:47 EDT 2009

On Mar 24, 2009, at 8:48 AM, Matthew Wilder wrote:

> Hi Owen,
> I agree that there should be some amount of rationing of IP  
> Addresses in the IPv4 endgame.  I simply question the fairness of a  
> policy that says everyone can have what they need in IPv4 addresses  
> except those who need more than a /20 every 6 months.
> Fairness itself is a loaded word in these discussions.  To me,  
> fairness in this case fundamentally implies equal access to IPv4  
> addresses.  The question then becomes the definition of equal  
> access.  Is that access to an equal amount of space per  
> organization?  Though that sounds good, that answer ignores the  
> philosophy of needs-based allocations.  And what about equal amount  
> of space per EU organization represented by an ISP?  That would  
> imply that the large ISPs should still have access to the majority  
> of IP Addresses, since they represent the vast majority of internet  
> users in North America.
> The starting point for this policy has to be some kind of target  
> objective.  If the objective of the policy is to make the last /9 of  
> space last around one year before depletion, without consideration  
> of consistent limitation to vastly different organizations, I think  
> this policy fits the bill.
> I think there is a way of making the last /9 last for a year without  
> unequally affecting different organizations.  I think the way to  
> implement such a policy more fairly is to limit allocations to a  
> certain percentage of space an organization already has allocated to  
> it.  Thus, each organization can have equal geometric growth to  
> their IPv4 address space, and thus everyone has the same limitations  
> placed on them.  I don't know the numbers that would accomplish a  
> goal of 1 year spreadout of the last /9, but I would bet it is in  
> the 5-10% ballpark.  Note that this kind of policy would prevent a  
> run on ARIN by smaller ISPs and EUs that can request a /20 which  
> might double their IPv4 address space.
I think it would be closer to 1%.  Let's look at that in real terms,  

For an organization that has an effective /10 worth of space, 1% is more
than 40,000 addresses.  On the other hand, for an organization that
has a /22, 1% is 10 addresses.  I really don't think the argument that  
is an equal impact on the small provider and the large one holds in such
a comparison. True, as a growth percentage, the effect is roughly the  
but, in real terms, 1% of a /10 allows the large ISP to add a number of
large customers, lots of medium customers and/or a whole lot of small
customers. On the other hand, for the small provider, those 10  
even if we're generous and bump them up to a /28 (16 addresses) to make
things line up are probably nearly useless.  First, they can only add  
small customer or a handful of home users.  Second, it's unlikely they  
even get the prefix routed, so, maybe they can't even do that.

Even if we use 10%, the numbers are still pretty skewed.  True, the  
provider now gets, essentially, a /25 to use for growth.  They might  
be able to put 8-16 small customers into that space.  There's even a  
chance they could get it routed.  But, the large ISP with a /10 under  
system gets a nice juicy /13 or so (more than 400,000 addresses).

However, with 24 x-large organizations (many of whom have more than
a /8, not just a /10 under their control) vying for this remaining /9,  
10%, I don't think you'll get anywhere close to a year.

You do raise some interesting questions.  It would be good to get a
sense from the community of:

1.	How long would the community like rationed IPv4 to last?
	A.	Brick Wall -- allocate as we have until it's gone.
	B.	Ration by some mechanism to last 1 year
	C.	Ration for 2 years
	D.	Ration for 5 years

2.	How would the community prefer to ration?
	A.	Percentage of existing space
	B.	Nobody gets more than a /x every 6 months
	C.	A graduated table based on your org. type:
			(example only:
					x-large		<=/18 every 6 months
					large		<=/19 every 6 months
					medium		<=/20 every 6 months
					smaller		<=/22 every 6 months

3.	How does the community feel we should balance the conflicting needs
	of large quantities of addresses for large ISPs vs. large numbers of
	smaller organizations needing fewer addresses each?

I don't really have a strong opinion on how this should go.  But, I  
think it is
important we have the discussion and come to a deliberate decision as
a community in the near future.


More information about the ARIN-PPML mailing list