IP Address Blocks ARIN Issues From

ARIN IPv4 Address Blocks

ARIN (or its predecessor registries) have performed allocation and assignment of IPv4 address blocks from specific address blocks assigned by IANA. The list of IPv4 address blocks is available here on the IANA website.

ARIN’s free pool of IPv4 address space was depleted on 24 September 2015. As a result, we are no longer fulfilling requests for IPv4 addresses directly from a free pool. All approved IPv4 requests are placed on our waiting list for unmet requests. There are exceptions in special cases outlined by policy, such as:

  • NRPM Section 4.10: Organizations may request a /24 of IPv4 address space to facilitate their IPv6 deployment. ARIN is issuing blocks out of per NRPM Section 4.10. Per policy, this block is subject to a minimum size allocation of /28 and a maximum size allocation of /24. ARIN uses sparse allocation when possible within this /10 block.
  • NRPM Section 4.4: Micro-allocations can be provided to critical Internet infrastructure providers such as exchange point operators and core DNS service providers. We provide a list of micro-allocations.

ARIN also facilitates IPv4 transfers and maintains a listing of transferred address space.

ARIN IPv6 Allocation Blocks

List of IPv6 prefixes that have been set aside for ARIN to allocate from.

  • 2001:0400::/23
  • 2001:1800::/23
  • 2001:4800::/23
  • 2600:0000::/12 [1]
  • 2610:0000::/23

[1] ARIN is issuing IPv6 transitional technology blocks from 2602:0000::/16. For more information, please see NRPM Section

ARIN IPv6 Assignment Blocks

List of IPv6 prefixes that have been set aside for ARIN to assign from.

  • 2620:0000::/23