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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 209.41.0.0/18 | 16.4k | ARIN |  US | 5th Jan 2001 |
| 209.44.0.0/18 | 16.4k | ARIN | US | 26th Mar 1997 |
| 209.46.104.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 209.46.112.0/22 | 1k | ARIN | US | 20th Jul 2023 |
| 209.46.128.0/17 | 32.8k | ARIN | US | 28th Apr 1997 |
| 209.46.16.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 209.46.34.0/23 | 512 | ARIN | US | 22nd Apr 1997 |
| 209.46.36.0/24 | 256 | ARIN | US | 22nd Apr 1997 |
| 209.46.4.0/22 | 1k | ARIN | US | 26th Feb 2025 |
| 209.46.40.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 209.46.60.0/22 | 1k | ARIN | US | 20th Jul 2023 |
| 209.46.72.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 209.46.80.0/20 | 4.1k | ARIN | US | 19th Jul 2023 |
| 209.54.192.0/18 | 16.4k | ARIN | US | 22nd Jun 2011 |
| 209.59.224.0/24 | 256 | ARIN | US | 12th Oct 2020 |
| 209.59.225.0/24 | 256 | ARIN | US | 20th Dec 2018 |
| 209.59.247.0/24 | 256 | ARIN | US | 12th Feb 2019 |
| 209.62.0.0/17 | 32.8k | ARIN | US | 19th Mar 2007 |
| 209.62.128.0/19 | 8.2k | ARIN | US | 2nd Mar 1999 |
| 209.66.0.0/18 | 16.4k | ARIN | US | 7th Apr 1997 |
| 209.66.128.0/19 | 8.2k | ARIN | US | 14th Apr 1997 |
| 209.66.224.0/19 | 8.2k | ARIN | US | 2nd Jun 2000 |
| 209.74.96.0/21 | 2k | ARIN | US | 26th Jun 2000 |
| 209.82.128.0/19 | 8.2k | ARIN | US | 15th May 1997 |
| 209.87.170.0/24 | 256 | ARIN | US | 7th Apr 1999 |
| 209.90.192.0/19 | 8.2k | ARIN | US | 6th May 2004 |
| 209.92.32.0/22 | 1k | ARIN | US | 12th May 2025 |
| 209.92.70.0/23 | 512 | ARIN | US | 4th Jun 1997 |
| 209.94.49.0/24 | 256 | ARIN | US | 13th Sept 2022 |
| 209.94.71.0/24 | 256 | ARIN | US | 18th Jul 2022 |
| 209.94.78.0/24 | 256 | ARIN | US | 22nd Dec 2017 |
| 209.94.92.0/23 | 512 | ARIN | US | 22nd Dec 2017 |
| 209.95.160.0/19 | 8.2k | ARIN | US | 26th Sept 1997 |
| 209.95.192.0/19 | 8.2k | ARIN | US | 3rd Oct 1997 |
| 209.95.64.0/19 | 8.2k | ARIN | US | 19th Aug 1997 |
| 209.97.96.0/20 | 4.1k | ARIN | US | 23rd Mar 2001 |
| 209.99.128.0/20 | 4.1k | ARIN | US | 16th Jul 1997 |
| 209.99.168.0/21 | 2k | ARIN | US | 26th Jun 2026 |
| 209.99.176.0/21 | 2k | ARIN | US | 24th Jul 2026 |
| 209.99.240.0/20 | 4.1k | ARIN | US | 6th Sept 2001 |
| 212.224.48.0/20 | 4.1k | ARIN | US | 3rd Jun 2024 |
| 213.239.137.0/24 | 256 | ARIN | US | 13th May 2026 |
| 216.10.192.0/20 | 4.1k | ARIN | US | 23rd Dec 1999 |
| 216.10.235.0/24 | 256 | ARIN | US | 22nd Jul 2011 |
| 216.10.53.0/24 | 256 | ARIN | US | 22nd Mar 2024 |
| 216.10.54.0/24 | 256 | ARIN | US | 22nd Mar 2024 |
| 216.10.62.0/23 | 512 | ARIN | US | 22nd Mar 2024 |
| 216.10.77.0/24 | 256 | ARIN | US | 25th Oct 2019 |
| 216.10.80.0/20 | 4.1k | ARIN | US | 7th Sept 2004 |
| 216.105.160.0/22 | 1k | ARIN | US | 29th Jun 2000 |