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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,461 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 216.99.205.0/24 | 256 | ARIN |  US | 14th Dec 2015 |
| 216.99.208.0/23 | 512 | ARIN | US | 7th Mar 2016 |
| 216.99.96.0/20 | 4.1k | ARIN |  CA | 28th Oct 1998 |
| 217.159.0.0/17 | 32.8k | ARIN | US | 14th Nov 2022 |
| 220.158.32.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 23.111.8.0/22 | 1k | ARIN | US | 24th Jul 2013 |
| 23.128.172.0/24 | 256 | ARIN | US | 6th Nov 2024 |
| 23.128.192.0/24 | 256 | ARIN | US | 14th Jul 2017 |
| 23.128.196.0/24 | 256 | ARIN | US | 7th Nov 2024 |
| 23.128.212.0/24 | 256 | ARIN |  BS | 7th Nov 2024 |
| 23.128.52.0/24 | 256 | ARIN | US | 22nd Oct 2024 |
| 23.128.82.0/24 | 256 | ARIN | CA | 10th Nov 2021 |
| 23.128.84.0/24 | 256 | ARIN | US | 28th Oct 2024 |
| 23.128.88.0/24 | 256 | ARIN | US | 10th Nov 2021 |
| 23.128.98.0/24 | 256 | ARIN | US | 23rd Nov 2022 |
| 23.129.128.0/24 | 256 | ARIN | US | 21st Dec 2016 |
| 23.129.132.0/24 | 256 | ARIN | US | 18th Nov 2024 |
| 23.129.48.0/24 | 256 | ARIN | US | 21st Mar 2019 |
| 23.129.49.0/24 | 256 | ARIN | US | 25th Jun 2021 |
| 23.129.82.0/24 | 256 | ARIN | US | 9th Dec 2021 |
| 23.130.100.0/24 | 256 | ARIN | US | 5th Dec 2024 |
| 23.130.106.0/24 | 256 | ARIN | US | 14th Jan 2022 |
| 23.130.107.0/24 | 256 | ARIN | US | 14th Jan 2022 |
| 23.130.132.0/24 | 256 | ARIN | US | 6th Dec 2024 |
| 23.130.168.0/24 | 256 | ARIN |  GD | 20th Jan 2022 |
| 23.130.224.0/24 | 256 | ARIN |  VG | 16th May 2018 |
| 23.130.244.0/24 | 256 | ARIN | US | 16th Dec 2024 |
| 23.131.0.0/24 | 256 | ARIN | US | 17th May 2016 |
| 23.131.140.0/24 | 256 | ARIN | US | 31st Dec 2024 |
| 23.131.240.0/24 | 256 | ARIN | US | 19th Apr 2019 |
| 23.131.48.0/24 | 256 | ARIN | US | 8th Apr 2019 |
| 23.131.80.0/24 | 256 | ARIN | US | 10th Apr 2019 |
| 23.132.128.0/24 | 256 | ARIN | US | 9th Jan 2017 |
| 23.132.136.0/24 | 256 | ARIN | US | 25th Feb 2022 |
| 23.132.137.0/24 | 256 | ARIN | US | 25th Feb 2022 |
| 23.132.20.0/24 | 256 | ARIN | US | 8th Jan 2025 |
| 23.132.240.0/24 | 256 | ARIN | US | 1st May 2019 |
| 23.132.248.0/24 | 256 | ARIN | CA | 3rd Mar 2022 |
| 23.133.12.0/24 | 256 | ARIN | US | 23rd Jan 2025 |
| 23.133.128.0/24 | 256 | ARIN | US | 23rd Jan 2017 |
| 23.133.16.0/24 | 256 | ARIN | US | 1st May 2019 |
| 23.133.168.0/24 | 256 | ARIN | CA | 17th Mar 2022 |
| 23.133.180.0/24 | 256 | ARIN | US | 3rd Feb 2025 |
| 23.133.36.0/24 | 256 | ARIN | US | 24th Jan 2025 |
| 23.133.44.0/24 | 256 | ARIN | US | 24th Jan 2025 |
| 23.133.6.0/24 | 256 | ARIN | US | 24th May 2016 |
| 23.133.92.0/24 | 256 | ARIN | US | 29th Jan 2025 |
| 23.133.96.0/24 | 256 | ARIN | US | 31st May 2018 |
| 23.134.100.0/24 | 256 | ARIN | US | 12th Feb 2025 |
| 23.134.116.0/24 | 256 | ARIN | US | 13th Feb 2025 |