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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
Browse by registry
Browse by country
Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,273 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 130.250.135.0/24 | 256 | ARIN |  US | 17th Feb 2016 |
| 130.250.156.0/24 | 256 | ARIN | US | 17th Feb 2016 |
| 130.250.168.0/23 | 512 | ARIN | US | 17th Feb 2016 |
| 130.250.172.0/23 | 512 | ARIN | US | 17th Feb 2016 |
| 130.250.198.0/24 | 256 | ARIN | US | 17th Feb 2016 |
| 130.27.0.0/16 | 65.5k | ARIN | US | 28th Apr 1988 |
| 130.29.0.0/16 | 65.5k | ARIN | US | 28th Apr 1988 |
| 130.30.0.0/16 | 65.5k | ARIN | US | 28th Apr 1988 |
| 130.38.0.0/16 | 65.5k | ARIN | US | 4th May 1988 |
| 130.4.0.0/14 | 262k | ARIN | US | 25th Sept 1992 |
| 130.42.0.0/16 | 65.5k | ARIN | US | 13th Jun 1988 |
| 130.44.25.0/24 | 256 | ARIN | US | 13th May 1988 |
| 130.48.0.0/16 | 65.5k | ARIN | US | 16th May 1988 |
| 130.51.109.0/24 | 256 | ARIN | US | 5th Jun 2024 |
| 130.51.160.0/24 | 256 | ARIN | US | 30th Jan 2020 |
| 130.51.162.0/23 | 512 | ARIN | US | 17th Jan 2020 |
| 130.51.244.0/22 | 1k | ARIN | US | 24th Jan 2020 |
| 130.51.252.0/22 | 1k | ARIN | US | 10th Feb 2020 |
| 130.51.34.0/23 | 512 | ARIN | US | 6th Oct 2025 |
| 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 |
| 131.143.0.0/22 | 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 |
| 131.143.222.0/24 | 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 |