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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,430 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 66.85.32.0/23 | 512 | ARIN | US | 1st Jul 2026 |
| 66.85.36.0/22 | 1k | ARIN | US | 6th Jul 2026 |
| 66.85.40.0/24 | 256 | ARIN |  AG | 1st Jul 2026 |
| 66.85.58.0/24 | 256 | ARIN | US | 2nd Jul 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 |
| 66.85.7.0/24 | 256 | ARIN | US | 29th Sept 2020 |
| 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 |
| 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 |
| 67.158.96.0/19 | 8.2k | ARIN | US | 10th Feb 2026 |
| 67.199.240.0/23 | 512 | ARIN | US | 3rd May 2016 |
| 67.199.242.0/24 | 256 | ARIN | US | 3rd May 2016 |
| 67.199.246.0/24 | 256 | ARIN | US | 30th Aug 2016 |
| 67.202.233.0/24 | 256 | ARIN | US | 7th Sept 2007 |
| 67.203.101.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 67.203.102.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 67.203.109.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 67.203.121.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 67.203.123.0/24 | 256 | ARIN | US | 13th Feb 2012 |