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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
26,973 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 170.39.40.0/22 | 1k | ARIN |  US | 29th Jun 2020 |
| 170.39.44.0/22 | 1k | ARIN | US | 7th Jul 2020 |
| 170.39.56.0/22 | 1k | ARIN | US | 24th Aug 2020 |
| 170.39.60.0/22 | 1k | ARIN | US | 29th Jun 2020 |
| 170.39.7.0/24 | 256 | ARIN | US | 21st Aug 2020 |
| 170.39.92.0/22 | 1k | ARIN | US | 8th Sept 2020 |
| 170.4.128.0/19 | 8.2k | ARIN | US | 2nd Dec 1993 |
| 170.4.160.0/21 | 2k | ARIN | US | 2nd Dec 1993 |
| 170.4.208.0/20 | 4.1k | ARIN | US | 2nd Dec 1993 |
| 170.42.0.0/15 | 131k | ARIN | US | 9th Feb 1994 |
| 170.44.0.0/15 | 131k | ARIN | US | 9th Feb 1994 |
| 170.50.0.0/16 | 65.5k | ARIN | US | 10th Feb 1994 |
| 170.52.192.0/18 | 16.4k | ARIN | US | 10th Apr 2017 |
| 170.52.20.0/22 | 1k | ARIN | US | 14th Feb 1994 |
| 170.52.24.0/21 | 2k | ARIN | US | 14th Feb 1994 |
| 170.52.40.0/24 | 256 | ARIN | US | 14th Feb 1994 |
| 170.53.0.0/16 | 65.5k | ARIN | US | 15th Feb 1994 |
| 170.59.0.0/16 | 65.5k | ARIN | US | 18th Feb 1994 |
| 170.62.120.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.124.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.163.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.174.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.191.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.192.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.200.0/23 | 512 | ARIN | US | 22nd Feb 1994 |
| 170.62.204.0/24 | 256 | ARIN | US | 19th Jul 2024 |
| 170.62.205.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.208.0/20 | 4.1k | ARIN | US | 22nd Feb 1994 |
| 170.62.248.0/23 | 512 | ARIN | US | 22nd Feb 1994 |
| 170.62.251.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.254.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.32.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.33.0/24 | 256 | ARIN | US | 21st Aug 2023 |
| 170.62.36.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.40.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.80.0/24 | 256 | ARIN | US | 22nd Feb 1994 |
| 170.62.84.0/22 | 1k | ARIN | US | 21st Aug 2023 |
| 170.67.0.0/16 | 65.5k | ARIN | US | 25th Feb 1994 |
| 170.71.0.0/16 | 65.5k | ARIN | US | 6th Feb 2012 |
| 170.73.0.0/16 | 65.5k | ARIN | US | 3rd Mar 1994 |
| 170.76.0.0/17 | 32.8k | ARIN | US | 20th Dec 2018 |
| 170.76.130.0/24 | 256 | ARIN | US | 7th Nov 2016 |
| 170.76.134.0/24 | 256 | ARIN | US | 17th Apr 2017 |
| 170.76.210.0/24 | 256 | ARIN | US | 13th Dec 2017 |
| 170.76.220.0/23 | 512 | ARIN | US | 17th Jan 2018 |
| 170.76.228.0/23 | 512 | ARIN | US | 27th Mar 2018 |
| 170.76.231.0/24 | 256 | ARIN | US | 22nd May 2018 |
| 170.76.239.0/24 | 256 | ARIN | US | 9th Oct 2018 |
| 170.76.240.0/24 | 256 | ARIN | US | 20th Apr 2020 |
| 170.81.124.0/22 | 1k | ARIN | US | 11th Jan 2022 |