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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,295 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 216.52.242.0/23 | 512 | ARIN |  US | 24th Aug 1998 |
| 216.52.246.0/23 | 512 | ARIN | US | 24th Aug 1998 |
| 216.52.249.0/24 | 256 | ARIN | US | 5th Aug 2026 |
| 216.52.36.0/22 | 1k | ARIN | US | 24th Aug 1998 |
| 216.52.40.0/22 | 1k | ARIN | US | 24th Aug 1998 |
| 216.52.96.0/22 | 1k | ARIN | US | 24th Aug 1998 |
| 216.57.121.0/24 | 256 | ARIN | US | 12th Aug 2005 |
| 216.58.176.0/20 | 4.1k | ARIN | US | 10th Mar 2005 |
| 216.69.64.0/19 | 8.2k | ARIN | US | 23rd Oct 1998 |
| 216.7.96.0/20 | 4.1k | ARIN | US | 5th Jan 2001 |
| 216.71.240.0/20 | 4.1k | ARIN | US | 4th May 2005 |
| 216.71.96.0/22 | 1k | ARIN | US | 24th Sept 2018 |
| 216.73.187.0/24 | 256 | ARIN | US | 8th Oct 2021 |
| 216.73.191.0/24 | 256 | ARIN | US | 8th Oct 2021 |
| 216.73.220.0/22 | 1k | ARIN | US | 10th Jun 1999 |
| 216.82.240.0/20 | 4.1k | ARIN | US | 17th Sept 2003 |
| 216.83.96.0/19 | 8.2k | ARIN | US | 15th Sept 2000 |
| 216.9.162.0/24 | 256 | ARIN | US | 27th Jul 2021 |
| 216.9.163.0/24 | 256 | ARIN | US | 18th Oct 1999 |
| 216.9.164.0/24 | 256 | ARIN | US | 2nd Aug 2021 |
| 216.9.32.0/20 | 4.1k | ARIN | US | 12th Oct 1999 |
| 216.98.16.0/20 | 4.1k | ARIN | US | 31st Oct 2000 |
| 216.98.168.0/22 | 1k | ARIN | US | 13th Oct 1998 |
| 216.98.174.0/24 | 256 | ARIN | US | 21st Sept 2016 |
| 216.99.199.0/24 | 256 | ARIN | US | 19th Nov 2015 |
| 216.99.205.0/24 | 256 | ARIN | US | 14th Dec 2015 |
| 216.99.208.0/23 | 512 | ARIN | US | 7th Mar 2016 |
| 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 |
| 23.128.52.0/24 | 256 | ARIN | US | 22nd Oct 2024 |
| 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 |
| 23.130.244.0/24 | 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 |