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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,277 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 149.112.75.0/24 | 256 | ARIN |  US | 9th Oct 2023 |
| 149.112.76.0/24 | 256 | ARIN | US | 9th Oct 2023 |
| 149.112.8.0/24 | 256 | ARIN | US | 16th Sept 2020 |
| 149.112.81.0/24 | 256 | ARIN | US | 28th Dec 2023 |
| 149.112.82.0/24 | 256 | ARIN | US | 28th Dec 2023 |
| 149.112.83.0/24 | 256 | ARIN | US | 2nd Jan 2024 |
| 149.112.85.0/24 | 256 | ARIN | US | 8th Feb 2024 |
| 149.112.86.0/23 | 512 | ARIN | US | 15th Feb 2024 |
| 149.112.88.0/24 | 256 | ARIN | US | 27th Feb 2024 |
| 149.112.94.0/24 | 256 | ARIN | US | 19th Apr 2024 |
| 149.112.95.0/24 | 256 | ARIN | US | 22nd Apr 2024 |
| 149.112.96.0/22 | 1k | ARIN | US | 19th Apr 2024 |
| 149.121.0.0/16 | 65.5k | ARIN | US | 26th Nov 1997 |
| 149.122.0.0/16 | 65.5k | ARIN | US | 19th Feb 1993 |
| 149.124.0.0/16 | 65.5k | ARIN | US | 3rd Mar 1993 |
| 149.131.128.0/20 | 4.1k | ARIN | US | 16th Apr 1991 |
| 149.131.144.0/21 | 2k | ARIN | US | 16th Apr 1991 |
| 149.131.152.0/21 | 2k | ARIN | US | 16th Apr 1991 |
| 149.131.160.0/19 | 8.2k | ARIN | US | 16th Apr 1991 |
| 149.131.192.0/18 | 16.4k | ARIN | US | 16th Apr 1991 |
| 149.137.208.0/22 | 1k | ARIN | US | 6th Apr 2020 |
| 149.141.0.0/16 | 65.5k | ARIN | US | 24th Apr 1991 |
| 149.145.0.0/16 | 65.5k | ARIN | US | 26th Apr 1991 |
| 149.19.5.0/24 | 256 | ARIN | US | 2nd Nov 2020 |
| 149.19.64.0/19 | 8.2k | ARIN | US | 8th Dec 2020 |
| 149.20.224.0/21 | 2k | ARIN | US | 26th Apr 2018 |
| 149.218.128.0/17 | 32.8k | ARIN | US | 7th Aug 2024 |
| 149.234.234.0/23 | 512 | ARIN | US | 25th Jan 2017 |
| 149.234.236.0/22 | 1k | ARIN | US | 25th Jan 2017 |
| 149.252.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 149.39.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.42.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.45.0.0/16 | 65.5k | ARIN | US | 12th Sept 2018 |
| 149.47.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.55.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.73.0.0/16 | 65.5k | ARIN | US | 26th Oct 1994 |
| 149.83.0.0/16 | 65.5k | ARIN | US | 1st Sept 1993 |
| 149.97.64.0/20 | 4.1k | ARIN | US | 29th Oct 2019 |
| 149.97.84.0/22 | 1k | ARIN | US | 29th Oct 2019 |
| 149.97.88.0/23 | 512 | ARIN | US | 29th Oct 2019 |
| 149.97.92.0/22 | 1k | ARIN | US | 29th Oct 2019 |
| 15.100.0.0/15 | 131k | ARIN | US | 1st Jul 1994 |
| 15.102.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.104.0.0/13 | 524k | ARIN | US | 1st Jul 1994 |
| 15.112.0.0/12 | 1M | ARIN | US | 1st Jul 1994 |
| 15.139.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.151.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.163.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.173.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |
| 15.189.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |