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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,963 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 149.234.236.0/22 | 1k | ARIN |  US | 25th Jan 2017 |
| 149.25.0.0/16 | 65.5k | ARIN | US | 22nd Apr 1993 |
| 149.252.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 149.39.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.42.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.45.0.0/16 | 65.5k | ARIN | US | 12th Sept 2018 |
| 149.47.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.55.0.0/16 | 65.5k | ARIN | US | 28th Jan 1992 |
| 149.73.0.0/16 | 65.5k | ARIN | US | 26th Oct 1994 |
| 149.83.0.0/16 | 65.5k | ARIN | US | 1st Sept 1993 |
| 149.97.64.0/20 | 4.1k | ARIN | US | 29th Oct 2019 |
| 149.97.82.0/24 | 256 | ARIN | US | 10th Jun 2024 |
| 149.97.84.0/22 | 1k | ARIN | US | 29th Oct 2019 |
| 149.97.88.0/23 | 512 | ARIN | US | 29th Oct 2019 |
| 149.97.92.0/22 | 1k | ARIN | US | 29th Oct 2019 |
| 15.100.0.0/15 | 131k | ARIN | US | 1st Jul 1994 |
| 15.102.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.104.0.0/13 | 524k | ARIN | US | 1st Jul 1994 |
| 15.112.0.0/12 | 1M | ARIN | US | 1st Jul 1994 |
| 15.139.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.151.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.163.0.0/16 | 65.5k | ARIN | US | 1st Jul 1994 |
| 15.173.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |
| 15.189.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |
| 15.203.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |
| 15.225.0.0/16 | 65.5k | ARIN | US | 9th Nov 2023 |
| 15.226.0.0/16 | 65.5k | ARIN | US | 9th Nov 2023 |
| 15.243.0.0/16 | 65.5k | ARIN | US | 9th Nov 2023 |
| 15.96.0.0/14 | 262k | ARIN | US | 1st Jul 1994 |
| 150.102.0.0/16 | 65.5k | ARIN | US | 25th Jan 2024 |
| 150.103.0.0/16 | 65.5k | ARIN | US | 25th Jan 2024 |
| 150.110.0.0/16 | 65.5k | ARIN | US | 4th Jun 1991 |
| 150.123.0.0/16 | 65.5k | ARIN | US | 12th Sept 1991 |
| 150.124.0.0/16 | 65.5k | ARIN | US | 12th Sept 1991 |
| 150.127.0.0/16 | 65.5k | ARIN | US | 12th Sept 1991 |
| 150.141.0.0/16 | 65.5k | ARIN | US | 16th May 1991 |
| 150.159.0.0/16 | 65.5k | ARIN | US | 20th May 1991 |
| 150.166.0.0/16 | 65.5k | ARIN | US | 20th May 1991 |
| 150.170.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 150.172.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 150.190.0.0/16 | 65.5k | ARIN | US | 30th May 1991 |
| 150.195.240.0/20 | 4.1k | ARIN | US | 25th Jan 2021 |
| 150.215.0.0/16 | 65.5k | ARIN | US | 11th Jun 1991 |
| 150.222.0.0/16 | 65.5k | ARIN | US | 27th Dec 2017 |
| 150.225.0.0/16 | 65.5k | ARIN | US | 5th Aug 1991 |
| 150.233.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.234.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.235.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.247.128.0/17 | 32.8k | ARIN | US | 5th Aug 1991 |
| 150.247.48.0/20 | 4.1k | ARIN | US | 5th Aug 1991 |