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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 148.191.0.0/16 | 65.5k | ARIN |  US | 22nd May 1991 |
| 148.192.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.193.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.194.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.222.158.0/24 | 256 | ARIN | US | 24th Apr 2025 |
| 148.224.48.0/22 | 1k | ARIN | US | 22nd May 2025 |
| 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 |