Draft Policy 2010-2: /24 End User Minimum Assignment Unit [Archived]


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Status: NRPM Section and 4.3.6

Tracking Information

Discussion Tracking

Mailing List:

Formal introduction on PPML on 21 January 2010

Origin - Policy Proposal 99

Draft Policy - 21 January 2010 (with staff assessment)

Revised - 2 March 2010

Last Call - 28 April thru 12 May 2010

Remains on AC’s docket - 25 May 2010

Petition period extended - 11 June 2010

AC recommended adoption - 22 June 2010

Adopted and implemented - 9 September 2010

Public Policy Mailing List

ARIN Public Policy Meeting:


ARIN Advisory Council:

AC Shepherds:
Owen DeLong and Dan Alexander

ARIN Board of Trustees:

9 July 2010


Previous version(s)


9 September 2010

Draft Policy 2010-2
24 End User Minimum Assignment Unit

Version/Date: 2 March 2010

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.

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

Add the following paragraph Additional 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 4.3 assignments with a /23 or longer prefix 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.


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 table.

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.

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 providers.

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.
Timetable for implementation: Immediate


Here in the Vault, information is published in its final form and then not changed or updated. As a result, some content, specifically links to other pages and other references, may be out-of-date or no longer available.