[arin-ppml] New version of Proposal 99

Owen DeLong owen at delong.com
Tue Aug 11 20:04:11 EDT 2009

The proposal below is intended to clarify some things and address the  
comments and
questions from staff in their clarity and understanding document.

Comments, suggestions, and feedback are welcome.



1. Policy Proposal Name: /24 End User Minimum Allocation Unit 2.  
Proposal Originator
        a.      name: Owen DeLong
        b.      email: owen at delong.com
        c.      telephone: 408-890-7992
        d.      organization: Hurricane Electric

3. Proposal Version: 1.0
4. Date: 8/11/09
5. Proposal type: new
6. Policy term: permanent
7. Policy statement:

Replace section of the NRPM with the following: Multihomed Connection

For multi-homed end-users who demonstrate an intent to announce the  
requested space in a multihomed fashion to two or more distinct ASNs  
not owned or controlled by the end-user, the minimum block of IP  
address space assigned is a /24. If assignments smaller than a /24 are  
needed, multihomed end-users should contact their upstream providers.  
When prefixes are assigned which are longer than /20, they will be  
from a block reserved for that purpose so long as that is feasible.  
End-users may not receive a block smaller than /22 under this policy  
if they already have IPv4 resources from ARIN, except as specified in  

Renumber the existing paragraph under the 4.3.6 to Utilization requirements for additional Assignment

Add the following paragraph Replacement assignments for small multi-homers

Any end-user that possesses an assignment smaller than /22 under any  
part of section 4.3 shall not be able to get an additional assignment  
unless they agree to return all existing assignments within 12 months  
of receiving a new assignment. The new assignment shall be sized to  
accommodate their existing utilization in addition to their justified  
additional growth space under section The common cases for  
this are expected to be a /24 returned after receipt of a /23, or a / 
23 returned after receipt of a /22.

8. Rationale:

This policy attempts to incorporate the recent and historical  
discussions of policy for multi-home users on PPML. The intent is to  
provide as fair a process as possible for multi-homed organizations  
down to the smallest feasible size while still preserving some control  
over growth in the routing table.

It has been repeatedly noted that /24 multi-homers exist today with PA  
space and still occupy a routing table slot, so, it is unlikely that  
moving this boundary to /24 would significantly impact the routing  

By requiring smaller assignments to renumber and return, rather than  
add more small blocks to their assignments, this policy seeks to  
further reduce the chances of unnecessary growth in the routing table  
and encourage good aggregation where possible.

FAQs and responses to Staff Questions

Does this apply only to end users? Yes, this policy applies only to  
end users. This policy does not represent a good solution for  
organizations that are delegating space to other entities. If a case  
can be made that such a policy is needed for ISPs, then, the author is  
happy to work with interested parties to craft such a policy, but,  
this policy would be unnecessarily onerous on ISPs, and, as an ISP  
policy could be somewhat onerous to their peers and/or upstream  

What about resources obtained from policies other than 4.3 or outside  
of ARIN? Such resources would not be counted for excluding an  
organization from this policy. The intent is to limit IPv4 micro- 
allocations for multi-homed end-user organizations under this policy  
to a single assignment unless each such assignment is /22 or larger.  
This is to prevent unnecessary routing table growth. This is a  
tradeoff, and, not the ideal solution for smaller end-user  
organizations, however, author believes that this is the best policy  
likely to gain consensus at this time and believes that it is  
incrementally far better for such organizations than current policy.

If I grow, I have to renumber? Not necessarily... If you have a /24  
under this policy, and you want to grow that, then, you will likely  
need to renumber. Depending on ARIN resource management and timing,  
ARIN may simply be able to give you the /23 that includes your /24.  
More likely, you will get a new /23, have 1 year to renumber into that  
and return your /24. At most, you would be subject to two such  
renumbering cycles under this policy (24->23 and 23->22) before you  
meet the criteria for other policies which do not require renumbering.

Other policies don't include renumbering provisions, why this one? The  
policy which allows multi-homed organizations to get a /22 was  
originally written at /24. That policy was shouted down and /22 was  
the compromise achieved to gain community consensus for anything  
smaller than /20. Author hopes that this compromise will allow many  
organizations to get resources they need with minimal impact while  
assuring the community that doing so will not cause an explosion in  
the routing table.

9. Timetable for implementation: Immediate


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