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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,277 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 179.255.80.0/20 | 4.1k | ARIN |  US | 13th Mar 2025 |
| 179.67.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 179.69.128.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 184.128.0.0/12 | 1M | ARIN | US | 25th Feb 2010 |
| 184.170.144.0/20 | 4.1k | ARIN | US | 18th May 2011 |
| 184.172.0.0/15 | 131k | ARIN | US | 6th Oct 2010 |
| 184.88.0.0/14 | 262k | ARIN | US | 31st Mar 2010 |
| 184.95.16.0/20 | 4.1k | ARIN | US | 14th Aug 2024 |
| 185.144.68.0/23 | 512 | ARIN | US | 19th Sept 2024 |
| 185.159.89.0/24 | 256 | ARIN | US | 13th Oct 2025 |
| 185.167.182.0/24 | 256 | ARIN | US | 9th Jun 2022 |
| 185.176.52.0/22 | 1k | ARIN | US | 19th Feb 2019 |
| 185.20.220.0/22 | 1k | ARIN | US | 11th May 2017 |
| 185.203.207.0/24 | 256 | ARIN | US | 11th Apr 2022 |
| 185.39.52.0/22 | 1k | ARIN | US | 22nd Jun 2020 |
| 185.74.168.0/22 | 1k | ARIN | US | 4th Apr 2022 |
| 185.77.4.0/23 | 512 | ARIN | US | 13th Feb 2020 |
| 185.81.136.0/22 | 1k | ARIN | US | 22nd Jun 2020 |
| 185.90.244.0/22 | 1k | ARIN | US | 15th Jun 2017 |
| 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 |
| 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 |
| 189.106.0.0/15 | 131k | ARIN | US | 29th Jul 2026 |
| 189.12.0.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 189.24.128.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 189.31.224.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 189.48.0.0/16 | 65.5k | ARIN | US | 29th Jul 2026 |