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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
26,971 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 141.124.0.0/16 | 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 |
| 141.206.160.0/19 | 8.2k | ARIN | US | 16th Oct 1992 |
| 141.224.112.0/20 | 4.1k | ARIN | US | 14th Jun 2024 |
| 141.226.138.0/24 | 256 | ARIN | US | 6th Jul 2017 |
| 141.240.0.0/16 | 65.5k | ARIN | US | 10th Aug 1990 |
| 141.247.0.0/16 | 65.5k | ARIN | US | 21st Jun 1994 |
| 141.251.0.0/16 | 65.5k | ARIN | US | 22nd Jun 2011 |
| 142.0.68.0/22 | 1k | ARIN | US | 26th Jun 2024 |
| 142.11.128.0/18 | 16.4k | ARIN | US | 19th Jun 2012 |
| 142.11.64.0/18 | 16.4k | ARIN | US | 19th Jun 2012 |
| 142.147.14.0/24 | 256 | ARIN | US | 24th Aug 2015 |
| 142.196.0.0/15 | 131k | ARIN | US | 8th May 2012 |