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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,954 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 66.179.120.0/21 | 2k | ARIN |  US | 9th Oct 2001 |
| 66.179.128.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 66.179.144.0/22 | 1k | ARIN | US | 16th Jan 2024 |
| 66.179.162.0/23 | 512 | ARIN | US | 9th Oct 2001 |
| 66.179.164.0/23 | 512 | ARIN | US | 9th Oct 2001 |
| 66.179.170.0/23 | 512 | ARIN | US | 3rd Aug 2026 |
| 66.179.180.0/22 | 1k | ARIN | US | 19th Jan 2024 |
| 66.179.184.0/22 | 1k | ARIN | US | 9th Oct 2001 |
| 66.179.192.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 66.179.200.0/23 | 512 | ARIN | US | 17th Jul 2024 |
| 66.179.22.0/24 | 256 | ARIN | US | 21st Jul 2023 |
| 66.179.232.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 66.179.24.0/22 | 1k | ARIN | US | 9th Oct 2001 |
| 66.179.28.0/24 | 256 | ARIN | US | 9th Oct 2001 |
| 66.179.32.0/22 | 1k | ARIN | US | 9th Oct 2001 |
| 66.179.38.0/23 | 512 | ARIN | US | 24th Jul 2024 |
| 66.179.40.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 66.180.208.0/20 | 4.1k | ARIN | US | 9th May 2006 |
| 66.180.64.0/24 | 256 | ARIN | US | 30th Sept 2016 |
| 66.180.68.0/22 | 1k | ARIN |  CA | 19th Dec 2016 |
| 66.181.96.0/20 | 4.1k | ARIN | US | 24th Oct 2001 |
| 66.182.96.0/20 | 4.1k | ARIN | US | 26th Mar 2024 |
| 66.186.112.0/20 | 4.1k | ARIN | US | 10th Jan 2006 |
| 66.186.194.0/23 | 512 | RIPE NCC |  AL | 9th Nov 2001 |
| 66.187.14.0/24 | 256 | ARIN | CA | 26th Dec 2024 |
| 66.187.3.0/24 | 256 | ARIN | US | 27th Apr 2021 |
| 66.196.128.0/18 | 16.4k | ARIN | US | 22nd Jul 2020 |
| 66.203.250.0/24 | 256 | ARIN | US | 4th Dec 2025 |
| 66.203.251.0/24 | 256 | ARIN | US | 15th Jan 2026 |
| 66.203.255.0/24 | 256 | ARIN | US | 3rd Jun 2026 |
| 66.205.228.0/22 | 1k | ARIN | US | 26th Sept 2019 |
| 66.205.234.0/24 | 256 | ARIN | US | 9th Sept 2019 |
| 66.205.240.0/23 | 512 | ARIN | US | 4th Sept 2019 |
| 66.206.208.0/20 | 4.1k | ARIN | US | 16th Jun 2008 |
| 66.206.64.0/20 | 4.1k | ARIN | US | 7th Dec 2001 |
| 66.207.48.0/23 | 512 | ARIN | US | 22nd Mar 2024 |
| 66.207.56.0/22 | 1k | ARIN | US | 15th Mar 2006 |
| 66.208.84.0/22 | 1k | ARIN | CA | 1st Jul 2026 |
| 66.208.92.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 66.209.0.0/19 | 8.2k | ARIN | US | 21st Dec 2001 |
| 66.209.144.0/20 | 4.1k | ARIN | US | 4th Mar 2003 |
| 66.211.172.0/22 | 1k | ARIN | US | 25th Jan 2006 |
| 66.212.48.0/23 | 512 | ARIN | US | 27th Mar 2017 |
| 66.220.32.0/22 | 1k | ARIN | US | 18th Jan 2002 |
| 66.220.36.0/24 | 256 | ARIN | US | 18th Jan 2002 |
| 66.220.39.0/24 | 256 | ARIN | US | 24th Feb 2022 |
| 66.220.40.0/23 | 512 | ARIN | US | 18th Jan 2002 |
| 66.220.44.0/23 | 512 | ARIN | US | 18th Jan 2002 |
| 66.220.52.0/23 | 512 | ARIN | US | 17th Jan 2025 |
| 66.220.54.0/24 | 256 | ARIN | US | 17th Mar 2022 |