[arin-ppml] LAST CALL: Recommended Draft Policy ARIN-2019-3: Update 4.10 – IPv6 Deployment Block

ARIN info at arin.net
Wed Nov 6 12:57:49 EST 2019

The ARIN Advisory Council (AC) met on 1 November 2019 and decided to 
send the following Recommended Draft Policy to Last Call:

ARIN-2019-3: Update 4.10 – IPv6 Deployment Block

Feedback is encouraged during the Last Call period. All comments should 
be provided to the Public Policy Mailing List. Last Call will expire on 
20 November 2019.

The Recommended Draft Policy text is below and available at:

The ARIN Policy Development Process is available at:


Sean Hopkins
Policy Analyst
American Registry for Internet Numbers (ARIN)

Recommended Draft Policy ARIN-2019-3: Update 4.10 – IPv6 Deployment Block

AC Assessment of Conformance with the Principles of Internet Number 
Resource Policy:

Because it will better enable fair number distribution, provide improved 
clarity and compatibility with existing systems, is technically sound, 
has received the support of the community, and there are no material 
legal issues related to implementation, the ARIN Advisory Council moved 
draft policy 2019-3 to recommended draft status.

Problem Statement:

ARIN staff has noted that the current 4.10 policy is causing problems in 
its implementation.

The current policy specifies a /28 minimum. However, ARIN can only 
allocated a /24 as its minimum size. ARIN’s current tools only support a 
minimum of /24 for reverse DNS.

The current RPKI landscape is also an impediment to using smaller block 
sizes. Furthermore, a /28 practically is unroutable, so an organization 
if they were to receive a /28 would be unable to functionally 
interoperate with most IPv4 end points, for applications which were 
noted examples in the original policy. (At the time of writing the 
original policy, it was hoped that by creating a policy with a smaller 
block size other RIRs and network operators would embrace the routing of 
blocks smaller than a /24.)

Updating ARINs tools to allow smaller than a /24 for reverse DNS (such 
as RFC2317) would likely be a large cost compared value received by the 
community. This value is further diminished because the purpose of an 
IPv4 block to facilitate IPv6 deployment is that it be routable to the 
rest of the IPv4 Internet.

This policy attempts to address these issues, by raising the minimum 
size to a /24 and limits total amount an organization can receive to a 
/21. It also removes the requirement for return and renumber, since that 
was primarily added to allow organizations to obtain larger blocks if 
that was necessary. The policy also clarifies the utilization 
requirements by placing them directly in this section rather than a 
reference to the utilization requirements of end users.

Policy Statement:

Replace current 4.10 with the following updated section

4.10 Dedicated IPv4 block to facilitate IPv6 Deployment

ARIN shall allocate a contiguous /10 from its last /8 IPv4 allocation 
from IANA. This IPv4 block will be set aside and dedicated to facilitate 
IPv6 deployment. Allocations and assignments from this block must be 
justified by immediate IPv6 deployment requirements. Examples of such 
needs include: IPv4 addresses for key dual stack DNS servers, and NAT-PT 
or NAT464 translators. ARIN staff will use their discretion when 
evaluating justifications.

This block will be subject to a minimum and maximum size allocation of 
/24. ARIN should use sparse allocation when possible within that /10 block.

In order to receive an allocation or assignment under this policy:

- the applicant may not have received resources under this policy in the 
preceding six months and cannot receive more than a /21 under this 
policy section;

- previous allocations/assignments under this policy must continue to 
meet the justification requirements of this policy;

- previous allocations/assignments under this policy must be utilized to 
at least 80% to obtain an additional allocation or assignment;

- the applicant must demonstrate that no other allocations or 
assignments will meet this need.

Timetable for Implementation: Immediate

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