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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,273 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 107.161.153.0/24 | 256 | ARIN |  US | 23rd Sept 2020 |
| 107.161.48.0/24 | 256 | ARIN | US | 13th Jan 2014 |
| 107.161.49.0/24 | 256 | ARIN | US | 6th Oct 2022 |
| 107.164.0.0/15 | 131k | ARIN | US | 21st Jun 2024 |
| 107.167.240.0/24 | 256 | ARIN | US | 23rd Dec 2024 |
| 107.167.244.0/22 | 1k | ARIN | US | 4th Feb 2014 |
| 107.176.0.0/15 | 131k | ARIN | US | 9th Mar 2020 |
| 107.182.137.0/24 | 256 | ARIN | US | 7th Apr 2021 |
| 107.182.48.0/20 | 4.1k | ARIN | US | 7th Feb 2014 |
| 107.184.0.0/15 | 131k | ARIN | US | 12th Feb 2014 |
| 107.190.160.0/20 | 4.1k | ARIN | US | 17th Apr 2014 |
| 107.191.240.0/20 | 4.1k | ARIN | US | 31st Dec 2018 |
| 107.191.64.0/23 | 512 | ARIN | US | 30th Apr 2019 |
| 107.191.69.0/24 | 256 | ARIN | US | 8th Apr 2019 |
| 107.191.70.0/23 | 512 | ARIN | US | 25th Mar 2019 |
| 107.191.75.0/24 | 256 | ARIN | US | 28th Mar 2018 |
| 107.6.64.0/21 | 2k | ARIN | US | 23rd Jul 2026 |
| 108.160.212.0/22 | 1k | ARIN | US | 5th Jan 2022 |
| 108.160.220.0/22 | 1k | ARIN | US | 13th Jan 2026 |
| 108.161.16.0/20 | 4.1k | ARIN | US | 19th Oct 2011 |
| 108.161.240.0/20 | 4.1k | ARIN | US | 11th Nov 2011 |
| 108.171.224.0/20 | 4.1k | ARIN | US | 5th Mar 2012 |
| 108.174.88.0/22 | 1k | ARIN | US | 18th Jun 2018 |
| 108.174.92.0/22 | 1k | ARIN | US | 25th Jul 2018 |
| 108.182.0.0/15 | 131k | ARIN | US | 30th Aug 2012 |
| 108.184.0.0/15 | 131k | ARIN | US | 24th Jan 2013 |
| 109.233.32.0/21 | 2k | ARIN | US | 13th Dec 2022 |
| 116.193.160.0/22 | 1k | ARIN | US | 13th Mar 2024 |
| 116.91.16.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 122.222.128.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 122.223.0.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 122.223.144.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 122.223.80.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 122.223.96.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 124.110.112.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 128.126.0.0/16 | 65.5k | ARIN | US | 15th May 1986 |
| 128.128.64.0/20 | 4.1k | ARIN | US | 21st May 1986 |
| 128.152.0.0/16 | 65.5k | ARIN | US | 9th Sept 1986 |
| 128.161.0.0/16 | 65.5k | ARIN | US | 24th Sept 1986 |
| 128.162.0.0/16 | 65.5k | ARIN | US | 24th Sept 1986 |
| 128.166.0.0/16 | 65.5k | ARIN | US | 29th Sept 1986 |
| 128.20.0.0/16 | 65.5k | ARIN | US | 12th May 1983 |
| 128.207.0.0/16 | 65.5k | ARIN | US | 5th Mar 1987 |
| 128.209.0.0/16 | 65.5k | ARIN | US | 14th Apr 2000 |
| 128.215.0.0/16 | 65.5k | ARIN | US | 16th Mar 1987 |
| 128.222.0.0/16 | 65.5k | ARIN | US | 24th Mar 1987 |
| 128.225.0.0/16 | 65.5k | ARIN | US | 7th Apr 1987 |
| 128.247.0.0/16 | 65.5k | ARIN | US | 28th May 1987 |
| 128.254.0.0/17 | 32.8k | ARIN | US | 4th Jun 1987 |
| 128.254.152.0/22 | 1k | ARIN | US | 1st Jul 2026 |