[arin-ppml] Encouraging IPv6 route aggregation

[Scott Leibrand]

David Farmer wrote:
> I do believe it is important to deal with IPv6 route aggregation and 
> soon, because I also agree with Scott that "there isn't a lot of need 
> for doing so just yet".  But that is because the IPv6 toothpaste is 
> still mostly in the tube.  So while maybe we don't need it just yet, 
> we can't wait until we actually need it, it may be to late to 
> implement anything then.
>
> However, even with more and more IPv6 coming out of the toothpaste 
> tube everyday, I think we are better off in IPv6 than we are currently 
> in IPv4.  With IPv6 there is simply just more room to work with.  
> Which allows for a generous but limited set of allocation sizes from 
> the RIRs, with /32s for most ISPs and larger for really large ISPs.  
> With /48s from the RIRs for multihomed PI end-user assignments, or 
> /48s, /56s, /64s, or /128s to end-users from providers for PA 
> assignments.
>
> So today for IPv6 ARIN provides /32s or greater for PA allocations 
> from a set of ranges, the /48s or greater for PA end-user space from 
> another range (probably set of ranges in the future, but only one 
> range so far), and there several other special purpose ranges with a 
> /48 allocation/assignment sizes, this creates up a pretty reasonable 
> set of filtering policies that can be implemented by the operator 
> community. 

> If ARIN can maintain allocation and assignment policies that segregate 
> the types of allocations and assignments into separate documented 
> ranges I think it will be possible for the operator community to 
> maintain reasonable routing policy and filters to implement their 
> chosen policy.

Agreed.

>
> I believe the General Purpose ranges, along with the Critical 
> Infrastructure and maybe the Exchange Point Micro Allocation ranges, 
> should make up most of ARIN region's contribution to the mythical 
> global route table.
>
> An idea I've been kicking around is a class of end-user assignments 
> not intended for routing in the mythical global route table, but for 
> things like VPNs, and other private network needs, not necessarily 
> intended to have global reachability, but that needs global uniqueness 
> and reverse DNS.  Some of you say use ULA for that, but ULA only 
> provides statical uniqueness, not the guarantee of uniqueness that an 
> assignment authority can, and since there is no assignment authority 
> for ULA, authoritative reverse DNS is not possible. This would be 
> similar to NRPM 6.10.2 but for end-users and not ISPs, since 
> Micro-allocations for Internal Infrastructure are restricted to 
> "Organizations that currently hold IPv6 allocations".  I'd rather not 
> debate the merits of this idea now, but wanted to provide an example 
> that illustrates how ARIN policy can and should work with and enable 
> good routing policy.

Sounds like ULA-Global (which I supported).

>
> I'm not sure how many operators currently filter the Internal 
> Infrastructure Micro Allocation range 2001:0506::/31. ARIN policy 
> doesn't require anyone to do so, but by having it as a separate 
> documented range ARIN policy makes it possible for operators to have a 
> routing policy that filters it if they so desire.  Whereas if it were 
> not a separate documented range, it would probably be nearly 
> impossible to filter these allocations.
>
> So currently the main policy tool that ARIN, and the other RIRs have, 
> have that influences and enables routing policy is to create 
> classifications for allocations or assignments and to put them into 
> documented ranges.  So I believe we need to remember that RIR policy 
> has a responsibility the consider and implement at least this part of 
> routing policy.
>
> So lets think about applying this to the IPv6 policies on the table 
> right now;
>
> 2008-3 Community Networks IPv6 Assignment - It is probably kind of 
> late in the process for this, but maybe it would be a good idea for 
> these assignments to come out of separate documented range.

Do I recall correctly that ARIN staff said they would do so, even if not 
specifically required by policy?

>
> 2009-5 Multiple Discrete Networks - Should those allocations come out 
> of a separate documented range?

No.  These allocations are identical to other General Purpose 
allocations, except that an organization with multiple networks may have 
one for each network.

>
> 2009-7 Open Access To IPv6 - One of the things we are doing is 
> removing the requirement to advertise a singe aggregate of an 
> allocation. Rather than eliminating the restriction all together, it 
> might be better from a routing policy point of view to create a 
> separate documented range without the requirement to announce an 
> aggregate.  Maybe it is not unreasonable for this to have an extra fee 
> associated with an allocation out of this block too?  (Fees are not 
> directly a policy issue, but it could be a recommendation that the 
> Board consider an extra fee in this case.) I have heard some valid 
> reasons for some networks to not announce an aggregate of there IPv6 
> allocation, but I still believe most network can and should announce 
> an aggregate.  Maybe we shouldn't through the baby out with the bath 
> water on this one.  Creating a range for allocations without the 
> requirement for announcing an aggregate would allow operators to have 
> a routing policy to require it for the vast majority that can and 
> should announce an aggregate.

This seems like unnecessary complexity to me.

>
> Comments please, and please bend my ear in Dearborn next week on this 
> issue too.
>

Looking forward to it!

-Scott