ARIN distributes 73 IPv4 address
A recent allocation from the American Registry for Internet Numbers highlights how IPv4 scarcity continues to shape internet operations. ARIN’s waiting list process remains a key mechanism for organizations that still rely on the older addressing standard.
The American Registry for Internet Numbers (ARIN), the nonprofit body that manages internet number resources in the United States, Canada, and parts of the Caribbean, has announced the fulfilment of 73 requests for IPv4 address space from its waiting list on 3 April 2025. These requests drew from 63 IPv4 address blocks that had recently been cleared for reuse.
To understand why this matters, it helps to step back. IPv4 is the older addressing system that identifies devices on the internet. It was created in the early days of the network and provides around 4.3 billion possible addresses. That sounded sufficient several decades ago. Yet the explosive growth of connected devices exhausted most available IPv4 space in many regions years ago. ARIN formally ran out of freely available IPv4 addresses in 2015.
Since then, organisations that still depend on IPv4 must either purchase address space on the secondary market or join ARIN’s waiting list. The waiting list is a controlled mechanism that provides small allocations as addresses become available. usually through the return or revocation of unused space. These reissued blocks are vetted before distribution. When ARIN publishes the list of ‘cleared’ blocks, it signals that the blocks have been reviewed and are ready for reassignment.
Some of these blocks may previously have had a poor reputation. Perhaps because of past misuse by earlier holders. ARIN notes that earlier inferences about these blocks are likely no longer accurate. Once a block is reclaimed and reassigned, its association with old behaviour should not be assumed to persist. This clarification matters for network operators who rely on blocklists to filter unwanted traffic. Overly broad filtering can unintentionally harm legitimate organisations that receive reassigned address space.
ARIN provides more detail about how reclaimed IPv4 space is evaluated in its blog post on blocklist management. The post explains the risks of treating address blocks as permanently tainted and encourages operators to update their practices when reassigned space enters circulation.
Organisations interested in the status of available IPv4 allocations can review the current waiting list on ARIN’s website. The next round of distributions is scheduled for late in the second quarter of 2025. When ARIN will again notify the community and update the list of address blocks used to fulfil requests.
In an era where IPv4 scarcity persists. The waiting list remains an important tool for smaller organisations that cannot easily transition to IPv6 or purchase address space on the commercial market.
