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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
Browse by registry
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Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 185.39.52.0/22 | 1k | ARIN |  US | 22nd Jun 2020 |
| 185.40.24.0/22 | 1k | RIPE NCC | US | 11th Nov 2013 |
| 185.42.148.0/22 | 1k | RIPE NCC | US | 27th May 2019 |
| 185.42.204.0/22 | 1k | RIPE NCC | US | 11th Dec 2013 |
| 185.47.100.0/22 | 1k | RIPE NCC | US | 11th Feb 2014 |
| 185.56.200.0/22 | 1k | RIPE NCC | US | 6th May 2014 |
| 185.63.144.0/22 | 1k | RIPE NCC | US | 10th Jul 2014 |
| 185.69.156.0/22 | 1k | RIPE NCC | US | 9th Sept 2014 |
| 185.7.174.0/24 | 256 | RIPE NCC | US | 9th Jan 2025 |
| 185.72.103.0/24 | 256 | RIPE NCC | US | 17th Jan 2025 |
| 185.74.168.0/22 | 1k | ARIN | US | 4th Apr 2022 |
| 185.75.100.0/22 | 1k | RIPE NCC | US | 30th Oct 2014 |
| 185.77.224.0/22 | 1k | RIPE NCC | US | 4th Jul 2019 |
| 185.77.4.0/23 | 512 | ARIN | US | 13th Feb 2020 |
| 185.81.136.0/22 | 1k | ARIN | US | 22nd Jun 2020 |
| 185.83.156.0/23 | 512 | RIPE NCC | US | 9th Jan 2015 |
| 185.83.158.0/24 | 256 | RIPE NCC | US | 9th Jan 2015 |
| 185.90.244.0/22 | 1k | ARIN | US | 15th Jun 2017 |
| 185.97.88.0/22 | 1k | RIPE NCC | US | 22nd Apr 2015 |
| 186.242.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 186.245.0.0/16 | 65.5k | ARIN | US | 29th Jul 2026 |
| 187.126.128.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.13.32.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.41.128.0/17 | 32.8k | ARIN | US | 10th Apr 2026 |
| 187.42.192.0/18 | 16.4k | ARIN | US | 20th Feb 2025 |
| 187.52.224.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.52.32.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.53.160.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.54.0.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.54.224.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.55.128.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.55.160.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.55.64.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.7.192.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.7.32.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.78.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.78.128.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.78.192.0/18 | 16.4k | ARIN | US | 20th Feb 2025 |
| 187.79.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.79.128.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 188.209.144.0/21 | 2k | ARIN | US | 23rd Jul 2018 |
| 188.210.93.0/24 | 256 | RIPE NCC | US | 8th May 2009 |
| 188.213.23.0/24 | 256 | RIPE NCC | US | 8th May 2009 |
| 188.213.243.0/24 | 256 | RIPE NCC | US | 8th May 2009 |
| 188.241.193.0/24 | 256 | RIPE NCC | US | 23rd Jun 2009 |
| 188.64.143.0/24 | 256 | RIPE NCC | US | 13th Sept 2021 |
| 189.10.144.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 189.10.208.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 189.105.128.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 189.105.16.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |