ARIN-prop-335: Restrict the largest initial IPv6 allocation to /20

Date: 31 May 2024

Proposal Originator: Tyler O’Meara

Problem Statement:

In order to promote aggregation, the NRPM currently allows initial allocations up to a /16. However, the entire IPv6 address space only contains 65536 /16s, and the space allocated to IANA for globally routable purposes only contains 8192 /16s. Therefore, a /16 is a sufficiently large portion of the IPv6 address space that the goal of conservation starts to outweigh the goal of aggregation.

Policy Statement:

6.5.2.1b: Replace “In no case shall an ISP receive more than a /16 initial allocation.” with “In no case shall a LIR receive more than a /20 initial allocation.”

Comments: A quick look at ARIN’s stats shows that only a single IPv6 allocation exceeds a /20 in size:

grep “ipv6” delegated-arin-extended-latest | grep allocated | cut -d ‘|’ -f 5 | sort | uniq -c

1 16
8 20
22 22
39 24
2 27
127 28
15 29
6 30
21 31
4236 32
1 33
2 35
1401 36
1 37
1 38
1050 40
11 41
13 42
9 43
851 44
16 45
15 46
26 47
1754 48

Timetable for Implementation: Immediate