[arin-ppml] Why should we do Proposal 121

Owen DeLong owen at delong.com
Thu Dec 9 22:20:31 EST 2010

On Dec 9, 2010, at 11:33 AM, Charles O'Hern wrote:

> While I do support Proposal 121, I do have a concern/questions about Owen's first point.
> On 12/8/10 5:04 PM, Owen DeLong wrote:
>> I've been asked by a fellow AC member to spend some more effort documenting
>> reasons we should enact proposal 121.
>> 1.	Current IPv6 policy is being interpreted to the detriment of ISPs that
>> 	have subordinate ISPs. Subordinate ISPs should be able to get PA
>> 	space from their upstreams equivalent to what they would be able
>> 	to get directly from ARIN. Currently, ARIN is not allowing for the
>> 	possibility that an ISP would reallocate /32s (or larger) to their
>> 	subordinate ISPs.
> I think it is important to be careful here about two things.
> 1) While removing any obstacles or discouragement from subordinate ISPs receiving PA space is a good thing, we should take care that we don't end up discouraging the same ISPs from
> obtaining PI space instead.  I do not believe the current wording does this, but I think it is important to keep the point in mind for future edits.
I completely agree.

> 2) After the SWIP topics of this last year on the PPML list, I have this impression that record keeping across the ARIN region is a bit inconsistent and lacks automation.  I hate
> to bring up what seems to be a dead-horse topic, but should SWIP policy be modified in regards to any difference between subordinate ISPs and large end users?  Should there be a
> policy about SWIP auditing?  Does a multi-homed subordinate ISP, which qualifies for a /32 of PI from ARIN, qualify to get a /32 PA from each of its providers?  Given the size of
> v6 are we even concerned if they do so?  And what would that do to global routing table growth?
There are several questions there. I'll attempt to answer them in order.

1.	Perhaps, but, I think that is out of scope for this particular proposal. I do not believe
	this proposal makes the situation any worse than current. I would be happy
	to work with anyone who wants to write policy to address that issue.

2.	Same answer as the first question.

3.	I don't see any meaningful way to prevent this, but, I also do not see any advantage
	to the subordinate ISP from doing so. Their end-sites can each only count as
	utilization in one of the blocks.

4.	I suspect not especially.

5.	Nothing more than the single PI block from ARIN since the PA blocks would still
	be aggregates.

> and a personal ignorance question:  Does a subordinate ISP with X aggregate allocations advertised through Y direct upstream ISPs end up adding X x Y routes to the global tables?
No.. They end up adding X routes and X*Y Paths to the global tables.
However, paths are not the issue, prefixes are.

Also, the belief that they add X routes is based on the assumption that
none of those X routes are handled by an upstream providers aggregate


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