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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,989 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 140.232.94.0/23 | 512 | ARIN |  US | 21st May 1990 |
| 140.232.96.0/19 | 8.2k | ARIN | US | 21st May 1990 |
| 140.235.112.0/23 | 512 | ARIN | US | 3rd Oct 2024 |
| 140.235.114.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 140.235.120.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 140.235.126.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 140.235.127.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 140.235.152.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 140.235.185.0/24 | 256 | ARIN | US | 9th Oct 2024 |
| 140.235.186.0/23 | 512 | ARIN | US | 23rd Dec 2024 |
| 140.235.238.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 140.235.244.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 140.235.48.0/22 | 1k | ARIN | US | 4th Oct 2024 |
| 140.235.56.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 140.235.76.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 140.235.84.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 140.24.0.0/16 | 65.5k | ARIN | US | 8th Apr 1990 |
| 140.26.0.0/16 | 65.5k | ARIN | US | 8th Apr 1990 |
| 140.4.0.0/16 | 65.5k | ARIN | US | 8th Apr 1990 |
| 140.76.0.0/16 | 65.5k | ARIN | US | 9th Apr 1990 |
| 140.82.64.0/19 | 8.2k | ARIN | US | 30th May 2018 |
| 140.82.96.0/20 | 4.1k | ARIN | US | 30th May 2018 |
| 140.87.0.0/16 | 65.5k | ARIN | US | 9th Apr 1990 |
| 140.88.0.0/16 | 65.5k | ARIN | US | 9th Apr 1990 |
| 141.102.0.0/16 | 65.5k | ARIN | US | 6th Jul 1990 |
| 141.121.0.0/16 | 65.5k | ARIN | US | 20th Oct 1990 |
| 141.128.0.0/16 | 65.5k | ARIN | US | 20th Oct 1990 |
| 141.159.0.0/16 | 65.5k | ARIN | US | 24th Apr 1990 |
| 141.173.0.0/16 | 65.5k | ARIN | US | 24th Jan 1992 |
| 141.177.0.0/16 | 65.5k | ARIN | US | 30th Jan 1995 |
| 141.180.0.0/16 | 65.5k | ARIN | US | 26th Jul 1990 |
| 141.183.0.0/16 | 65.5k | ARIN | US | 26th Jul 1990 |
| 141.184.0.0/16 | 65.5k | ARIN | US | 26th Jul 1990 |
| 141.193.136.0/24 | 256 | ARIN | US | 12th Apr 2021 |
| 141.193.139.0/24 | 256 | ARIN | US | 5th Apr 2021 |
| 141.193.144.0/22 | 1k | ARIN | US | 6th Aug 2018 |
| 141.193.148.0/24 | 256 | ARIN | US | 6th Jul 2020 |
| 141.193.150.0/24 | 256 | ARIN | US | 14th Sept 2020 |
| 141.193.18.0/23 | 512 | ARIN | US | 26th May 2017 |
| 141.193.212.0/24 | 256 | ARIN | US | 1st Jun 2020 |
| 141.193.224.0/24 | 256 | ARIN | US | 19th Feb 2020 |
| 141.193.227.0/24 | 256 | ARIN | US | 8th May 2019 |
| 141.193.232.0/24 | 256 | ARIN | US | 12th Feb 2019 |
| 141.193.25.0/24 | 256 | ARIN | US | 18th Jul 2017 |
| 141.193.26.0/24 | 256 | ARIN | US | 1st Sept 2017 |
| 141.193.70.0/24 | 256 | ARIN | US | 9th Jun 2021 |
| 141.204.0.0/16 | 65.5k | ARIN | US | 3rd Aug 1990 |
| 141.205.0.0/16 | 65.5k | ARIN | US | 3rd Aug 1990 |
| 141.206.0.0/17 | 32.8k | ARIN | US | 16th Oct 1992 |
| 141.206.128.0/20 | 4.1k | ARIN | US | 16th Oct 1992 |