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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
26,951 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 209.127.205.0/24 | 256 | ARIN |  US | 8th Jan 2020 |
| 209.127.206.0/24 | 256 | ARIN | US | 31st Jan 2020 |
| 209.127.213.0/24 | 256 | ARIN | US | 5th May 2020 |
| 209.127.62.0/24 | 256 | ARIN | US | 12th Jan 2018 |
| 209.131.127.0/24 | 256 | ARIN | US | 10th Sept 2025 |
| 209.135.137.0/24 | 256 | ARIN | US | 12th Jun 2026 |
| 209.135.138.0/24 | 256 | ARIN | US | 2nd Oct 2026 |
| 209.135.148.0/23 | 512 | ARIN | US | 20th Aug 2026 |
| 209.135.150.0/24 | 256 | ARIN | US | 15th Sept 2026 |
| 209.135.157.0/24 | 256 | ARIN | US | 5th Sept 1997 |
| 209.135.158.0/24 | 256 | ARIN | US | 6th Aug 2026 |
| 209.135.160.0/22 | 1k | ARIN | US | 2nd Apr 2024 |
| 209.135.172.0/22 | 1k | ARIN | US | 4th Jun 2024 |
| 209.135.32.0/19 | 8.2k | ARIN | US | 28th Apr 2000 |
| 209.142.125.0/24 | 256 | ARIN | US | 28th Sept 2020 |
| 209.142.94.0/23 | 512 | ARIN | US | 6th Oct 2020 |
| 209.143.160.0/19 | 8.2k | ARIN | US | 6th Sept 2000 |
| 209.145.0.0/19 | 8.2k | ARIN | US | 26th Sept 1997 |
| 209.145.33.0/24 | 256 | ARIN | US | 27th Nov 2023 |
| 209.145.34.0/24 | 256 | ARIN | US | 27th Nov 2023 |
| 209.148.0.0/19 | 8.2k | ARIN | US | 30th Oct 1997 |
| 209.148.80.0/20 | 4.1k | ARIN | US | 24th Jun 2013 |
| 209.150.240.0/20 | 4.1k | ARIN | US | 5th Oct 2018 |
| 209.151.104.0/22 | 1k | ARIN | US | 3rd Apr 2024 |
| 209.151.125.0/24 | 256 | ARIN | US | 3rd Apr 2024 |
| 209.152.137.0/24 | 256 | ARIN | US | 20th Nov 2020 |
| 209.152.224.0/19 | 8.2k | ARIN | US | 14th Sept 2000 |
| 209.159.64.0/18 | 16.4k | ARIN | US | 17th May 2004 |
| 209.16.0.0/18 | 16.4k | ARIN | US | 24th Jan 1997 |
| 209.16.137.0/24 | 256 | ARIN | US | 1st Apr 2019 |
| 209.16.176.0/24 | 256 | RIPE NCC | US | 31st Jan 1997 |
| 209.16.178.0/24 | 256 | RIPE NCC | US | 31st Jan 1997 |
| 209.161.108.0/22 | 1k | ARIN | US | 7th Mar 2014 |
| 209.161.64.0/19 | 8.2k | ARIN | US | 10th Nov 1997 |
| 209.162.144.0/21 | 2k | RIPE NCC | US | 14th Nov 1997 |
| 209.162.152.0/23 | 512 | RIPE NCC | US | 14th Nov 1997 |
| 209.162.155.0/24 | 256 | RIPE NCC | US | 14th Nov 1997 |
| 209.162.156.0/24 | 256 | RIPE NCC | US | 14th Nov 1997 |
| 209.162.157.0/24 | 256 | RIPE NCC | US | 14th Nov 1997 |
| 209.162.158.0/23 | 512 | RIPE NCC | US | 14th Nov 1997 |
| 209.162.207.0/24 | 256 | ARIN | US | 2nd Oct 2026 |
| 209.162.208.0/21 | 2k | ARIN | US | 14th Jul 2026 |
| 209.162.221.0/24 | 256 | ARIN | US | 28th Jul 2026 |
| 209.163.124.0/22 | 1k | ARIN | US | 1st Jul 2025 |
| 209.164.32.0/20 | 4.1k | ARIN | US | 5th Nov 2026 |
| 209.169.32.0/19 | 8.2k | ARIN | US | 31st Jan 2006 |
| 209.17.192.0/19 | 8.2k | ARIN | US | 28th Feb 1997 |
| 209.17.224.0/19 | 8.2k | ARIN | US | 21st Aug 2000 |
| 209.173.56.0/23 | 512 | ARIN | US | 21st Mar 2001 |
| 209.173.59.0/24 | 256 | ARIN | US | 21st Mar 2001 |