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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,434 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 160.20.236.0/22 | 1k | ARIN |  US | 22nd Jan 2020 |
| 160.20.251.0/24 | 256 | ARIN | US | 6th Sept 2018 |
| 160.205.0.0/16 | 65.5k | ARIN | US | 2nd Jun 1997 |
| 160.229.0.0/16 | 65.5k | ARIN | US | 22nd Jun 1992 |
| 160.238.22.0/24 | 256 | ARIN | US | 14th Sept 2017 |
| 160.35.0.0/16 | 65.5k | ARIN | US | 21st Apr 1992 |
| 160.41.0.0/16 | 65.5k | ARIN | US | 21st Apr 1992 |
| 160.65.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1992 |
| 160.79.112.0/22 | 1k | ARIN | US | 20th Sept 2023 |
| 160.79.12.0/22 | 1k | ARIN | US | 4th Dec 2024 |
| 160.79.127.0/24 | 256 | ARIN | US | 19th Mar 2024 |
| 160.79.48.0/20 | 4.1k | ARIN | US | 11th Apr 2024 |
| 160.82.0.0/16 | 65.5k | ARIN | US | 28th Apr 1992 |
| 160.88.0.0/16 | 65.5k | ARIN | US | 29th Apr 1992 |
| 160.95.0.0/16 | 65.5k | ARIN | US | 4th May 1992 |
| 161.1.0.0/16 | 65.5k | ARIN | US | 20th Apr 1992 |
| 161.100.0.0/16 | 65.5k | ARIN | US | 23rd Jun 1992 |
| 161.101.0.0/16 | 65.5k | ARIN | US | 23rd Jun 1992 |
| 161.102.0.0/16 | 65.5k | ARIN | US | 23rd Jun 1992 |
| 161.103.0.0/16 | 65.5k | ARIN | US | 23rd Jun 1992 |
| 161.108.0.0/18 | 16.4k | ARIN | US | 25th Jun 1992 |
| 161.108.112.0/21 | 2k | ARIN | US | 25th Jun 1992 |
| 161.108.121.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 161.108.124.0/22 | 1k | ARIN | US | 25th Jun 1992 |
| 161.108.131.0/24 | 256 | ARIN | US | 16th Oct 2025 |
| 161.108.132.0/22 | 1k | ARIN | US | 25th Jun 1992 |
| 161.108.144.0/20 | 4.1k | ARIN | US | 25th Jun 1992 |
| 161.108.160.0/22 | 1k | ARIN | US | 25th Jun 1992 |
| 161.108.164.0/23 | 512 | ARIN | US | 25th Jun 1992 |
| 161.108.167.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 161.108.192.0/21 | 2k | ARIN | US | 21st Jul 2025 |
| 161.108.200.0/22 | 1k | ARIN | US | 25th Jun 1992 |
| 161.108.205.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 161.108.206.0/23 | 512 | ARIN | US | 25th Jun 1992 |
| 161.108.208.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 161.108.212.0/22 | 1k | ARIN | US | 25th Jun 1992 |
| 161.108.216.0/21 | 2k | ARIN | US | 25th Jun 1992 |
| 161.108.64.0/19 | 8.2k | ARIN | US | 25th Jun 1992 |
| 161.108.96.0/20 | 4.1k | ARIN | US | 25th Jun 1992 |
| 161.121.0.0/17 | 32.8k | ARIN | US | 14th Jul 1992 |
| 161.127.0.0/16 | 65.5k | ARIN | US | 23rd Jul 1992 |
| 161.128.0.0/16 | 65.5k | ARIN | US | 27th Jul 1992 |
| 161.129.177.0/24 | 256 | ARIN | US | 6th Aug 2018 |
| 161.129.189.0/24 | 256 | ARIN | US | 11th Apr 2018 |
| 161.129.191.0/24 | 256 | ARIN | US | 16th Apr 2018 |
| 161.129.246.0/23 | 512 | ARIN | US | 1st Aug 2018 |
| 161.129.30.0/24 | 256 | ARIN |  CA | 29th Mar 2018 |
| 161.129.63.0/24 | 256 | ARIN | US | 30th Mar 2018 |
| 161.129.96.0/19 | 8.2k | ARIN | CA | 29th Mar 2018 |
| 161.13.128.0/19 | 8.2k | ARIN | US | 3rd Mar 2026 |