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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
27,034 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.68.96.0/22 | 1k | ARIN |  US | 1st Dec 1993 |
| 199.7.0.0/20 | 4.1k | ARIN | US | 23rd Sept 1993 |
| 199.7.16.0/20 | 4.1k | ARIN | US | 14th Sept 1993 |
| 199.7.47.0/24 | 256 | ARIN | US | 13th Feb 2025 |
| 199.7.76.0/24 | 256 | ARIN | US | 7th Nov 2005 |
| 199.7.78.0/23 | 512 | ARIN | US | 7th Nov 2005 |
| 199.7.80.0/24 | 256 | ARIN | US | 7th Nov 2005 |
| 199.7.81.0/24 | 256 | ARIN | US | 29th Nov 2006 |
| 199.7.86.0/24 | 256 | ARIN | US | 2nd Sept 2004 |
| 199.7.88.0/23 | 512 | ARIN | US | 19th Jun 2007 |
| 199.7.92.0/24 | 256 | ARIN | US | 2nd Sept 2004 |
| 199.7.93.0/24 | 256 | ARIN | US | 27th Nov 2017 |
| 199.71.142.0/23 | 512 | ARIN | US | 4th Jun 2012 |
| 199.71.159.0/24 | 256 | ARIN | US | 31st Aug 2015 |
| 199.71.187.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.71.232.0/22 | 1k | ARIN | US | 6th Jan 2012 |
| 199.71.68.0/24 | 256 | ARIN | US | 13th Dec 2021 |
| 199.73.116.0/22 | 1k | ARIN | US | 10th Jan 2012 |
| 199.73.12.0/22 | 1k | ARIN | US | 11th Aug 2023 |
| 199.73.24.0/24 | 256 | ARIN | US | 2nd Dec 1993 |
| 199.73.40.0/23 | 512 | ARIN | US | 6th Dec 1993 |
| 199.73.64.0/20 | 4.1k | ARIN | US | 20th Dec 1993 |
| 199.73.8.0/23 | 512 | ARIN | US | 2nd Dec 1993 |
| 199.73.80.0/24 | 256 | ARIN | US | 20th Dec 1993 |
| 199.73.88.0/22 | 1k | ARIN | US | 5th Oct 2022 |
| 199.74.12.0/23 | 512 | ARIN | US | 6th Dec 1993 |
| 199.74.133.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.136.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.137.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.138.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.139.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.14.0/24 | 256 | ARIN | US | 6th Dec 1993 |
| 199.74.140.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.142.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.143.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.144.0/23 | 512 | ARIN | US | 22nd Jan 1994 |
| 199.74.146.0/23 | 512 | ARIN | US | 22nd Jan 1994 |
| 199.74.148.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.149.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.150.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.151.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.152.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.158.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.16.0/20 | 4.1k | ARIN | US | 3rd Dec 1993 |
| 199.74.160.0/23 | 512 | ARIN | US | 9th Jul 2012 |
| 199.74.163.0/24 | 256 | ARIN | US | 24th Jan 1994 |
| 199.74.164.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 199.74.166.0/24 | 256 | ARIN | US | 24th Jan 1994 |
| 199.74.167.0/24 | 256 | ARIN | US | 24th Jan 1994 |
| 199.74.168.0/24 | 256 | ARIN | US | 24th Jan 1994 |