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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,431 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 66.59.212.0/22 | 1k | ARIN |  US | 1st Apr 2024 |
| 66.59.222.0/23 | 512 | ARIN | US | 11th Jan 2022 |
| 66.6.48.0/22 | 1k | ARIN | US | 27th Dec 2023 |
| 66.6.60.0/22 | 1k | ARIN |  CA | 21st Dec 2023 |
| 66.6.80.0/20 | 4.1k | ARIN | US | 22nd Nov 2000 |
| 66.63.128.0/19 | 8.2k | ARIN | US | 16th May 2002 |
| 66.63.32.0/19 | 8.2k | ARIN | US | 12th Oct 2026 |
| 66.71.196.0/23 | 512 | ARIN |  JM | 21st Feb 2025 |
| 66.71.198.0/24 | 256 | ARIN | US | 9th Jan 2026 |
| 66.71.199.0/24 | 256 | ARIN | US | 21st Nov 2025 |
| 66.79.192.0/20 | 4.1k | ARIN | US | 2nd Sept 2026 |
| 66.79.208.0/21 | 2k | ARIN | US | 18th Sept 2026 |
| 66.79.216.0/21 | 2k | ARIN | US | 28th Oct 2003 |
| 66.81.0.0/23 | 512 | ARIN | US | 28th Feb 2001 |
| 66.81.103.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.104.0/23 | 512 | ARIN | US | 13th Feb 2012 |
| 66.81.120.0/22 | 1k | ARIN | US | 13th Feb 2012 |
| 66.81.132.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.14.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.15.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.159.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.32.0/22 | 1k | ARIN | US | 13th Feb 2012 |
| 66.81.40.0/21 | 2k | ARIN | US | 13th Feb 2012 |
| 66.81.50.0/23 | 512 | ARIN | US | 13th Feb 2012 |
| 66.81.52.0/22 | 1k | ARIN | US | 13th Feb 2012 |
| 66.81.7.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.81.84.0/22 | 1k | ARIN | US | 13th Feb 2012 |
| 66.81.95.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 66.84.80.0/24 | 256 | ARIN | US | 29th Jun 2026 |
| 66.85.0.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 66.85.192.0/19 | 8.2k | ARIN | US | 3rd Nov 2011 |
| 66.85.20.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 66.85.3.0/24 | 256 | ARIN | US | 24th Aug 2015 |
| 66.85.35.0/24 | 256 | ARIN | CA | 28th Aug 2026 |
| 66.85.61.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 66.85.64.0/23 | 512 | ARIN | US | 14th Mar 2019 |
| 66.85.66.0/24 | 256 | ARIN | US | 6th Jul 2026 |
| 66.86.0.0/16 | 65.5k | ARIN | US | 23rd Mar 2001 |
| 66.87.0.0/16 | 65.5k | ARIN | US | 27th Mar 2001 |
| 66.9.40.0/22 | 1k | ARIN | US | 22nd Jan 2024 |
| 66.94.224.0/19 | 8.2k | ARIN | US | 17th Jul 2003 |
| 66.97.0.0/20 | 4.1k | ARIN | US | 5th Apr 2001 |
| 66.97.125.0/24 | 256 | ARIN | US | 30th Mar 2020 |
| 66.97.167.0/24 | 256 | ARIN | US | 30th Jul 2019 |
| 66.97.172.0/23 | 512 | ARIN |  BM | 13th Jan 2017 |
| 66.97.178.0/24 | 256 | ARIN | US | 17th Oct 2017 |
| 66.97.184.0/22 | 1k | ARIN | US | 28th Feb 2017 |
| 67.150.0.0/16 | 65.5k | ARIN | US | 3rd May 2018 |
| 67.158.53.0/24 | 256 | ARIN | US | 30th Jan 2018 |
| 67.158.58.0/24 | 256 | ARIN | US | 23rd Mar 2018 |