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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 209.135.148.0/23 | 512 | ARIN |  US | 20th Aug 2026 |
| 209.135.150.0/23 | 512 | ARIN | US | 5th Sept 1997 |
| 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 |
| 209.140.64.0/18 | 16.4k | ARIN | US | 21st Jan 2011 |
| 209.142.114.0/24 | 256 | ARIN | US | 10th Nov 2020 |
| 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 |
| 209.151.104.0/22 | 1k | 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 |
| 209.161.64.0/19 | 8.2k | ARIN | US | 10th Nov 1997 |
| 209.161.96.0/20 | 4.1k | ARIN | US | 7th Mar 2014 |
| 209.162.207.0/24 | 256 | ARIN | US | 17th Nov 1997 |
| 209.162.208.0/21 | 2k | ARIN | US | 14th Jul 2026 |
| 209.162.216.0/22 | 1k | ARIN | US | 12th Jun 2026 |
| 209.162.221.0/24 | 256 | ARIN | US | 28th Jul 2026 |
| 209.163.105.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 209.163.114.0/24 | 256 | ARIN | US | 13th Mar 2024 |
| 209.163.124.0/22 | 1k | ARIN | US | 1st Jul 2025 |
| 209.166.192.0/18 | 16.4k | ARIN | US | 15th Jun 1999 |
| 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 |
| 209.173.60.0/22 | 1k | ARIN | US | 21st Mar 2001 |
| 209.176.0.0/16 | 65.5k | ARIN | US | 20th Nov 1997 |
| 209.177.178.0/23 | 512 | ARIN | US | 4th Jun 2008 |
| 209.177.180.0/22 | 1k | ARIN | US | 4th Jun 2008 |
| 209.177.184.0/21 | 2k | ARIN | US | 4th Jun 2008 |
| 209.177.76.0/24 | 256 | ARIN | US | 31st Jul 2025 |
| 209.177.78.0/24 | 256 | ARIN | US | 11th Sept 2017 |
| 209.178.202.0/24 | 256 | ARIN | US | 30th Sept 2024 |
| 209.178.240.0/22 | 1k | ARIN | US | 16th Jan 2024 |
| 209.178.247.0/24 | 256 | ARIN | US | 7th Sept 2023 |
| 209.178.248.0/22 | 1k | ARIN | US | 7th Sept 2023 |
| 209.18.0.0/19 | 8.2k | ARIN | US | 13th Jan 1997 |