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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,277 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 148.50.0.0/16 | 65.5k | ARIN |  US | 13th Mar 1991 |
| 148.52.160.0/19 | 8.2k | ARIN | US | 9th Sept 2025 |
| 148.59.114.0/24 | 256 | ARIN | US | 19th Apr 2018 |
| 148.59.138.0/24 | 256 | ARIN | US | 1st Jun 2026 |
| 148.59.144.0/24 | 256 | ARIN | US | 12th Apr 2017 |
| 148.59.155.0/24 | 256 | ARIN | US | 5th Feb 2018 |
| 148.59.166.0/23 | 512 | ARIN | US | 8th Dec 2017 |
| 148.59.206.0/23 | 512 | ARIN | US | 8th Aug 2016 |
| 148.59.24.0/24 | 256 | ARIN | US | 31st Aug 2020 |
| 148.59.26.0/24 | 256 | ARIN | US | 9th Oct 2020 |
| 148.59.43.0/24 | 256 | ARIN | US | 17th Aug 2018 |
| 148.59.92.0/24 | 256 | ARIN | US | 28th May 2020 |
| 148.72.129.0/24 | 256 | ARIN | US | 26th Oct 2015 |
| 148.72.146.0/23 | 512 | ARIN | US | 26th Oct 2015 |
| 148.72.148.0/24 | 256 | ARIN | US | 26th Oct 2015 |
| 148.72.150.0/23 | 512 | ARIN | US | 26th Oct 2015 |
| 148.72.156.0/23 | 512 | ARIN | US | 26th Oct 2015 |
| 148.72.180.0/22 | 1k | ARIN | US | 26th Oct 2015 |
| 148.72.184.0/21 | 2k | ARIN | US | 26th Oct 2015 |
| 148.78.67.0/24 | 256 | ARIN | US | 23rd Feb 2022 |
| 148.78.72.0/24 | 256 | ARIN | US | 23rd Feb 2022 |
| 148.78.77.0/24 | 256 | ARIN | US | 27th Dec 2017 |
| 148.78.78.0/23 | 512 | ARIN | US | 11th Apr 1991 |
| 148.78.96.0/23 | 512 | ARIN | US | 19th Feb 2020 |
| 148.89.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 148.90.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 148.91.0.0/16 | 65.5k | ARIN | US | 28th Jan 2021 |
| 148.92.0.0/16 | 65.5k | ARIN | US | 28th Jan 2021 |
| 148.93.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 148.95.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 148.96.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 148.97.0.0/16 | 65.5k | ARIN | US | 28th Jan 2021 |
| 148.98.0.0/16 | 65.5k | ARIN | US | 12th Apr 1991 |
| 149.103.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.112.0.0/24 | 256 | ARIN | US | 20th May 2020 |
| 149.112.1.0/24 | 256 | ARIN | US | 3rd Jun 2020 |
| 149.112.102.0/24 | 256 | ARIN | US | 15th May 2024 |
| 149.112.103.0/24 | 256 | ARIN | US | 27th Jun 2024 |
| 149.112.104.0/23 | 512 | ARIN | US | 10th Jun 2024 |
| 149.112.107.0/24 | 256 | ARIN | US | 16th Jul 2024 |
| 149.112.108.0/24 | 256 | ARIN | US | 18th Jul 2024 |
| 149.112.109.0/24 | 256 | ARIN | US | 2nd Aug 2024 |
| 149.112.11.0/24 | 256 | ARIN | US | 14th Oct 2020 |
| 149.112.113.0/24 | 256 | ARIN | US | 3rd Sept 2024 |
| 149.112.114.0/24 | 256 | ARIN | US | 9th Sept 2024 |
| 149.112.117.0/24 | 256 | ARIN | US | 20th Nov 2024 |
| 149.112.118.0/24 | 256 | ARIN | US | 2nd Dec 2024 |
| 149.112.128.0/24 | 256 | ARIN | US | 31st Dec 2024 |
| 149.112.13.0/24 | 256 | ARIN | US | 25th Jan 2021 |
| 149.112.132.0/24 | 256 | ARIN | US | 29th Apr 2025 |