Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,295 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 216.21.8.0/22 | 1k | ARIN |  US | 14th Apr 2025 |
| 216.211.196.0/24 | 256 | ARIN | US | 7th Apr 2023 |
| 216.211.219.0/24 | 256 | ARIN | US | 6th Apr 2023 |
| 216.213.16.0/21 | 2k | ARIN | US | 9th Aug 2017 |
| 216.216.0.0/15 | 131k | ARIN | US | 19th Nov 2024 |
| 216.219.96.0/20 | 4.1k | ARIN | US | 10th Nov 2000 |
| 216.223.48.0/22 | 1k | ARIN | US | 27th Apr 1999 |
| 216.224.192.0/23 | 512 | ARIN | US | 25th Sept 2006 |
| 216.224.196.0/23 | 512 | ARIN | US | 13th Dec 2013 |
| 216.224.200.0/21 | 2k | ARIN | US | 13th Dec 2013 |
| 216.224.208.0/23 | 512 | ARIN | US | 13th Dec 2013 |
| 216.225.16.0/21 | 2k | ARIN | US | 11th May 1999 |
| 216.225.208.0/20 | 4.1k | ARIN | US | 11th May 1999 |
| 216.230.180.0/22 | 1k | ARIN | US | 1st Apr 2024 |
| 216.230.188.0/22 | 1k | ARIN | US | 1st Apr 2024 |
| 216.230.66.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.8.0/23 | 512 | ARIN | US | 30th May 2018 |
| 216.230.82.0/24 | 256 | ARIN | US | 24th Aug 2020 |
| 216.230.83.0/24 | 256 | ARIN | US | 19th Feb 2015 |
| 216.230.85.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.88.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.90.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.234.129.0/24 | 256 | ARIN | US | 16th Jan 2025 |
| 216.234.133.0/24 | 256 | ARIN | US | 30th Apr 2020 |
| 216.234.136.0/24 | 256 | ARIN | US | 23rd Dec 2024 |
| 216.235.220.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 216.235.223.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 216.235.252.0/22 | 1k | ARIN | US | 30th Jan 2026 |
| 216.237.29.0/24 | 256 | ARIN | US | 15th Sept 1999 |
| 216.237.56.0/24 | 256 | ARIN | US | 15th Sept 1999 |
| 216.238.44.0/22 | 1k | ARIN | US | 1st Jul 2025 |
| 216.24.0.0/20 | 4.1k | ARIN | US | 21st Jul 1998 |
| 216.24.16.0/21 | 2k | ARIN | US | 21st Jul 1998 |
| 216.24.24.0/22 | 1k | ARIN | US | 21st Jul 1998 |
| 216.24.28.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.30.0/23 | 512 | ARIN | US | 21st Jul 1998 |
| 216.24.33.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.35.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.36.0/22 | 1k | ARIN | US | 21st Jul 1998 |
| 216.24.42.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.46.0/24 | 256 | ARIN | US | 8th Jul 2019 |
| 216.24.48.0/23 | 512 | ARIN | US | 21st Jul 1998 |
| 216.24.50.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.54.0/24 | 256 | ARIN | US | 26th May 2020 |
| 216.24.55.0/24 | 256 | ARIN | US | 4th Feb 2019 |
| 216.24.62.0/24 | 256 | ARIN | US | 2nd Dec 2020 |
| 216.240.96.0/20 | 4.1k | ARIN | US | 20th Sept 1999 |
| 216.243.80.0/20 | 4.1k | ARIN | US | 27th May 2005 |
| 216.245.130.0/23 | 512 | ARIN | US | 1st Jun 2023 |
| 216.245.160.0/20 | 4.1k | ARIN | US | 19th Jul 2023 |