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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,251 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 74.184.0.0/15 | 131k | ARIN |  US | 30th Oct 2006 |
| 74.187.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.189.0.0/16 | 65.5k | ARIN | US | 30th Oct 2006 |
| 74.201.16.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.168.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.196.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.210.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.212.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.220.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.230.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.232.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.238.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.24.0/21 | 2k | ARIN | US | 13th Nov 2006 |
| 74.201.242.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.246.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.205.200.0/22 | 1k | ARIN | US | 21st May 2024 |
| 74.205.247.0/24 | 256 | ARIN | US | 20th Nov 2023 |
| 74.206.0.0/19 | 8.2k | ARIN | US | 12th Oct 2006 |
| 74.209.166.0/23 | 512 | ARIN | US | 19th May 2009 |
| 74.209.178.0/23 | 512 | ARIN | US | 12th Jan 2026 |
| 74.209.183.0/24 | 256 | ARIN | US | 16th Apr 2026 |
| 74.212.128.0/21 | 2k | ARIN | US | 8th Dec 2006 |
| 74.212.140.0/22 | 1k | ARIN | US | 8th Dec 2006 |
| 74.212.184.0/21 | 2k | ARIN | US | 8th Dec 2006 |
| 74.217.36.0/22 | 1k | ARIN | US | 22nd Jan 2008 |
| 74.229.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.236.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.251.0.0/16 | 65.5k | ARIN | US | 17th Jan 2006 |
| 74.51.144.0/20 | 4.1k | ARIN | US | 31st Jul 2008 |
| 74.54.0.0/15 | 131k | ARIN | US | 17th Feb 2006 |
| 74.63.64.0/18 | 16.4k | ARIN | US | 13th Jun 2007 |
| 74.80.144.0/24 | 256 | ARIN | US | 20th Aug 2008 |
| 74.80.145.0/24 | 256 | ARIN | US | 14th Dec 2022 |
| 74.80.171.0/24 | 256 | ARIN | US | 20th Aug 2008 |
| 74.80.196.0/24 | 256 | ARIN | US | 9th Jun 2023 |
| 74.80.199.0/24 | 256 | ARIN | US | 3rd Oct 2022 |
| 74.80.205.0/24 | 256 | ARIN | US | 20th May 2022 |
| 74.80.209.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 74.80.224.0/24 | 256 | ARIN | US | 24th Apr 2023 |
| 74.80.229.0/24 | 256 | ARIN | US | 7th Jul 2022 |
| 74.81.171.0/24 | 256 | ARIN | US | 22nd Feb 2019 |
| 74.81.172.0/24 | 256 | ARIN | US | 22nd Feb 2019 |
| 74.81.186.0/24 | 256 | ARIN | US | 2nd Oct 2026 |
| 74.81.78.0/24 | 256 | ARIN | US | 5th Aug 2008 |
| 74.81.82.0/24 | 256 | ARIN | US | 5th Aug 2008 |
| 74.81.85.0/24 | 256 | ARIN | US | 5th Aug 2008 |
| 74.81.87.0/24 | 256 | ARIN | US | 5th Aug 2008 |
| 74.82.224.0/19 | 8.2k | ARIN | US | 3rd Feb 2010 |
| 74.85.153.0/24 | 256 | ARIN | US | 7th Nov 2016 |
| 75.119.160.0/20 | 4.1k | ARIN | US | 5th Mar 2021 |