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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,419 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 130.51.36.0/22 | 1k | ARIN |  US | 16th Mar 2021 |
| 130.51.44.0/22 | 1k | ARIN | US | 23rd Mar 2021 |
| 130.51.56.0/22 | 1k | ARIN | US | 3rd Apr 2024 |
| 130.51.68.0/22 | 1k | ARIN | US | 4th Apr 2024 |
| 130.51.77.0/24 | 256 | ARIN | US | 4th Apr 2024 |
| 130.51.79.0/24 | 256 | ARIN | US | 4th Apr 2024 |
| 130.72.0.0/16 | 65.5k | ARIN | US | 23rd Jun 1988 |
| 130.8.0.0/15 | 131k | ARIN | US | 25th Sept 1992 |
| 130.97.0.0/16 | 65.5k | ARIN | US | 13th Jul 1988 |
| 130.99.0.0/16 | 65.5k | ARIN | US | 14th Jul 1988 |
| 131.101.0.0/16 | 65.5k | ARIN | US | 3rd Nov 1988 |
| 131.110.0.0/16 | 65.5k | ARIN | US | 11th Nov 1988 |
| 131.124.0.0/16 | 65.5k | ARIN | US | 17th Nov 1988 |
| 131.125.64.0/18 | 16.4k | ARIN | US | 3rd May 2024 |
| 131.131.0.0/16 | 65.5k | ARIN | US | 22nd Sept 1988 |
| 131.133.0.0/16 | 65.5k | ARIN |  CA | 19th Jul 1989 |
| 131.140.0.0/15 | 131k | ARIN | CA | 21st Nov 1988 |
| 131.143.0.0/22 | 1k | ARIN | US | 8th Oct 2025 |
| 131.143.110.0/24 | 256 | ARIN | US | 10th Oct 2025 |
| 131.143.116.0/22 | 1k | ARIN | US | 7th Oct 2025 |
| 131.143.127.0/24 | 256 | ARIN | US | 13th Jan 2026 |
| 131.143.172.0/24 | 256 | ARIN | US | 27th Oct 2025 |
| 131.143.184.0/22 | 1k | ARIN | US | 7th Oct 2025 |
| 131.143.220.0/23 | 512 | ARIN |  AQ | 6th Oct 2025 |
| 131.143.222.0/24 | 256 | ARIN | US | 5th Nov 2025 |
| 131.143.223.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.228.0/22 | 1k | ARIN | US | 6th Oct 2025 |
| 131.143.236.0/23 | 512 | ARIN | US | 6th Oct 2025 |
| 131.143.238.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 131.143.24.0/22 | 1k | ARIN | US | 7th Oct 2025 |
| 131.143.254.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 131.143.40.0/23 | 512 | ARIN | US | 7th Oct 2025 |
| 131.143.44.0/23 | 512 | ARIN | US | 13th Jan 2026 |
| 131.143.53.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.55.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.56.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.57.0/24 | 256 | ARIN | US | 22nd Oct 2025 |
| 131.143.58.0/24 | 256 | ARIN | CA | 7th Oct 2025 |
| 131.143.60.0/23 | 512 | ARIN | US | 7th Oct 2025 |
| 131.143.68.0/22 | 1k | ARIN |  VI | 13th Jan 2026 |
| 131.143.78.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.79.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.143.81.0/24 | 256 | ARIN | US | 10th Oct 2025 |
| 131.143.82.0/24 | 256 | ARIN | CA | 17th Oct 2025 |
| 131.143.83.0/24 | 256 | ARIN | US | 10th Oct 2025 |
| 131.143.88.0/24 | 256 | ARIN | US | 8th Oct 2025 |
| 131.143.92.0/23 | 512 | ARIN | US | 7th Oct 2025 |
| 131.143.95.0/24 | 256 | ARIN | US | 7th Oct 2025 |
| 131.149.0.0/19 | 8.2k | ARIN | US | 27th Nov 2017 |
| 131.149.128.0/18 | 16.4k | ARIN | US | 27th Nov 2017 |