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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.26.235.0/24 | 256 | ARIN |  US | 6th Jan 1994 |
| 199.26.237.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.238.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.239.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.240.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.241.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.248.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.249.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.250.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.251.0/24 | 256 | ARIN | US | 6th Jan 1994 |
| 199.26.252.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.26.253.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.26.52.0/24 | 256 | ARIN | US | 12th Jan 1994 |
| 199.26.53.0/24 | 256 | ARIN | US | 28th Aug 2015 |
| 199.26.64.0/24 | 256 | ARIN | US | 3rd Jan 1994 |
| 199.26.65.0/24 | 256 | ARIN | US | 8th Oct 2015 |
| 199.27.136.0/21 | 2k | ARIN | US | 20th Aug 2010 |
| 199.27.208.0/22 | 1k | ARIN | US | 31st Aug 2010 |
| 199.27.24.0/22 | 1k | ARIN | US | 19th Oct 1993 |
| 199.27.28.0/23 | 512 | ARIN | US | 19th Oct 1993 |
| 199.28.0.0/16 | 65.5k | ARIN | US | 18th Oct 1993 |
| 199.30.108.0/22 | 1k | ARIN | US | 17th Dec 2019 |
| 199.30.132.0/22 | 1k | ARIN | US | 3rd Sept 2019 |
| 199.30.138.0/24 | 256 | ARIN | US | 21st Apr 2017 |
| 199.30.139.0/24 | 256 | ARIN | US | 11th May 2017 |
| 199.30.144.0/22 | 1k | ARIN | US | 7th Sept 2010 |
| 199.30.188.0/22 | 1k | ARIN | US | 13th Sept 2010 |
| 199.30.196.0/22 | 1k | ARIN | US | 13th Sept 2010 |
| 199.30.220.0/22 | 1k | ARIN | US | 23rd Dec 2024 |
| 199.30.224.0/22 | 1k | ARIN | US | 16th Sept 2010 |
| 199.30.244.0/22 | 1k | ARIN | US | 11th Mar 2025 |
| 199.30.32.0/21 | 2k | ARIN | US | 25th Oct 1993 |
| 199.30.40.0/22 | 1k | ARIN | US | 25th Oct 1993 |
| 199.30.44.0/23 | 512 | ARIN | US | 25th Oct 1993 |
| 199.30.80.0/22 | 1k | ARIN | US | 13th Jan 2026 |
| 199.33.0.0/21 | 2k | ARIN | US | 22nd Oct 1993 |
| 199.33.116.0/23 | 512 | ARIN | US | 7th Jul 2015 |
| 199.33.118.0/24 | 256 | ARIN | US | 11th Apr 2022 |
| 199.33.136.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.33.137.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.33.138.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.33.139.0/24 | 256 | ARIN | US | 7th Jan 1994 |
| 199.33.140.0/24 | 256 | ARIN | US | 4th Aug 2016 |
| 199.33.142.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.33.143.0/24 | 256 | ARIN | US | 3rd Sept 2015 |
| 199.33.144.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.33.145.0/24 | 256 | ARIN | US | 22nd Jan 2016 |
| 199.33.146.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.33.147.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.33.149.0/24 | 256 | ARIN | US | 10th Jan 1994 |