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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,253 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 1.178.68.0/22 | 1k | ARIN |  US | 13th Jan 2025 |
| 1.178.72.0/21 | 2k | ARIN | US | 13th Jan 2025 |
| 103.126.112.0/22 | 1k | ARIN | US | 18th Jun 2024 |
| 103.215.20.0/23 | 512 | ARIN | US | 3rd Feb 2025 |
| 103.239.232.0/24 | 256 | ARIN | US | 13th Nov 2024 |
| 103.43.152.0/22 | 1k | ARIN | US | 13th Mar 2024 |
| 103.8.239.0/24 | 256 | ARIN | US | 14th Mar 2022 |
| 104.128.176.0/24 | 256 | ARIN | US | 5th Apr 2021 |
| 104.128.68.0/23 | 512 | ARIN | US | 11th Apr 2024 |
| 104.129.224.0/20 | 4.1k | ARIN | US | 24th Jun 2014 |
| 104.143.12.0/22 | 1k | ARIN | US | 13th Sept 2019 |
| 104.152.192.0/22 | 1k | ARIN | US | 4th Aug 2014 |
| 104.152.8.0/21 | 2k | ARIN | US | 9th Jul 2014 |
| 104.153.20.0/22 | 1k | ARIN | US | 25th Jul 2014 |
| 104.153.200.0/22 | 1k | ARIN | US | 11th Aug 2014 |
| 104.153.88.0/22 | 1k | ARIN | US | 15th Apr 2025 |
| 104.156.128.0/22 | 1k | ARIN | US | 3rd Oct 2023 |
| 104.156.192.0/19 | 8.2k | ARIN | US | 17th Jul 2014 |
| 104.160.246.0/24 | 256 | ARIN | US | 31st Oct 2019 |
| 104.160.80.0/20 | 4.1k | ARIN | US | 17th Sept 2014 |
| 104.162.0.0/16 | 65.5k | ARIN | US | 28th Jul 2014 |
| 104.166.110.0/23 | 512 | ARIN | US | 6th Jul 2021 |
| 104.166.123.0/24 | 256 | ARIN | US | 7th Jan 2022 |
| 104.166.99.0/24 | 256 | ARIN | US | 7th Jan 2022 |
| 104.167.220.0/22 | 1k | ARIN | US | 7th Jan 2021 |
| 104.167.245.0/24 | 256 | ARIN | US | 6th Jan 2021 |
| 104.170.0.0/16 | 65.5k | ARIN | US | 10th Oct 2014 |
| 104.192.194.0/23 | 512 | ARIN | US | 22nd Aug 2022 |
| 104.192.30.0/24 | 256 | ARIN | US | 30th Oct 2024 |
| 104.192.73.0/24 | 256 | ARIN | US | 24th Apr 2017 |
| 104.193.112.0/22 | 1k | ARIN | US | 18th Sept 2014 |
| 104.193.16.0/21 | 2k | ARIN | US | 15th Sept 2014 |
| 104.193.28.0/22 | 1k | ARIN | US | 15th Sept 2014 |
| 104.193.80.0/21 | 2k | ARIN | US | 19th Sept 2014 |
| 104.193.96.0/22 | 1k | ARIN | US | 23rd Sept 2014 |
| 104.194.15.0/24 | 256 | ARIN | US | 1st Jul 2025 |
| 104.194.26.0/24 | 256 | ARIN | US | 24th Jul 2019 |
| 104.194.27.0/24 | 256 | ARIN | US | 15th Jul 2019 |
| 104.204.0.0/19 | 8.2k | ARIN | US | 6th Jul 2026 |
| 104.204.236.0/22 | 1k | ARIN | US | 26th Jun 2025 |
| 104.204.48.0/21 | 2k | ARIN | US | 10th Sept 2014 |
| 104.204.60.0/22 | 1k | ARIN | US | 6th Aug 2026 |
| 104.216.0.0/15 | 131k | ARIN | US | 6th Dec 2023 |
| 104.218.116.0/22 | 1k | ARIN | US | 8th Oct 2014 |
| 104.218.72.0/22 | 1k | ARIN | US | 10th May 2024 |
| 104.219.16.0/22 | 1k | ARIN | US | 15th Oct 2014 |
| 104.219.224.0/22 | 1k | ARIN | US | 31st Oct 2014 |
| 104.219.228.0/22 | 1k | ARIN | US | 5th Nov 2014 |
| 104.222.128.0/19 | 8.2k | ARIN | US | 6th Oct 2014 |
| 104.223.124.0/24 | 256 | ARIN | US | 2nd Oct 2014 |