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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
26,955 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 23.185.232.0/24 | 256 | ARIN |  US | 6th Aug 2024 |
| 23.186.176.0/24 | 256 | ARIN | US | 23rd Aug 2021 |
| 23.187.112.0/24 | 256 | ARIN | US | 26th Aug 2021 |
| 23.187.128.0/24 | 256 | ARIN | US | 23rd Jun 2017 |
| 23.187.168.0/24 | 256 | ARIN | US | 27th Aug 2024 |
| 23.187.209.0/24 | 256 | ARIN | US | 8th Nov 2024 |
| 23.188.192.0/24 | 256 | ARIN | US | 16th Apr 2018 |
| 23.188.21.0/24 | 256 | ARIN | US | 24th Sept 2021 |
| 23.188.40.0/24 | 256 | ARIN | US | 3rd Sept 2024 |
| 23.188.48.0/24 | 256 | ARIN | US | 10th Sept 2021 |
| 23.189.0.0/24 | 256 | ARIN | US | 29th Nov 2016 |
| 23.189.24.0/24 | 256 | ARIN | US | 5th Sept 2024 |
| 23.189.80.0/24 | 256 | ARIN | US | 18th Oct 2021 |
| 23.189.81.0/24 | 256 | ARIN | US | 18th Oct 2021 |
| 23.190.192.0/24 | 256 | ARIN | US | 18th Apr 2018 |
| 23.190.200.0/24 | 256 | ARIN | US | 2nd Oct 2024 |
| 23.190.24.0/24 | 256 | ARIN | US | 13th May 2026 |
| 23.190.49.0/24 | 256 | ARIN | US | 24th Sept 2021 |
| 23.190.50.0/24 | 256 | ARIN | US | 24th Sept 2021 |
| 23.190.51.0/24 | 256 | ARIN | US | 24th Sept 2021 |
| 23.190.64.0/24 | 256 | ARIN | US | 17th Apr 2018 |
| 23.190.8.0/24 | 256 | ARIN | US | 17th Sept 2024 |
| 23.190.80.0/21 | 2k | ARIN | US | 30th Sept 2021 |
| 23.191.208.0/24 | 256 | ARIN | US | 14th Oct 2021 |
| 23.191.24.0/24 | 256 | ARIN | US | 4th Oct 2024 |
| 23.191.56.0/24 | 256 | ARIN | US | 7th Oct 2024 |
| 23.226.144.0/20 | 4.1k | ARIN | US | 20th Sept 2013 |
| 23.227.0.0/19 | 8.2k | ARIN | US | 16th Sept 2013 |
| 23.228.0.0/18 | 16.4k | ARIN | US | 9th Sept 2013 |
| 23.246.132.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.162.0/23 | 512 | ARIN | US | 7th Jul 2026 |
| 23.246.172.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.176.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.192.0/18 | 16.4k | ARIN | US | 14th Nov 2013 |
| 23.247.140.0/22 | 1k | ARIN | US | 7th Oct 2021 |
| 23.247.176.0/22 | 1k | ARIN | US | 7th Apr 2025 |
| 23.247.184.0/23 | 512 | ARIN | US | 20th Oct 2021 |
| 23.247.186.0/24 | 256 | ARIN | US | 8th Oct 2021 |
| 23.247.224.0/22 | 1k | ARIN | US | 8th Oct 2021 |
| 23.247.244.0/22 | 1k | ARIN | US | 8th Oct 2021 |
| 23.247.254.0/23 | 512 | ARIN | US | 10th Nov 2021 |
| 23.249.144.0/20 | 4.1k | ARIN | US | 28th Sept 2018 |
| 23.249.166.0/24 | 256 | ARIN | US | 10th Mar 2020 |
| 23.29.160.0/19 | 8.2k | ARIN | US | 26th Mar 2012 |
| 23.92.96.0/20 | 4.1k | ARIN | US | 20th Aug 2013 |
| 24.110.10.0/24 | 256 | ARIN | US | 23rd Mar 2004 |
| 24.110.11.0/24 | 256 | ARIN | US | 19th Nov 2024 |
| 24.110.12.0/22 | 1k | ARIN | US | 19th Nov 2024 |
| 24.110.128.0/17 | 32.8k | ARIN | US | 19th Nov 2024 |
| 24.136.64.0/19 | 8.2k | ARIN | US | 13th Sept 2001 |