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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 16.202.0.0/16 | 65.5k | ARIN |  US | 18th May 1989 |
| 16.205.0.0/16 | 65.5k | ARIN | US | 4th Mar 2025 |
| 16.206.0.0/16 | 65.5k | ARIN | US | 4th Apr 2019 |
| 16.207.0.0/16 | 65.5k | ARIN | US | 9th Jan 2024 |
| 16.211.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.212.0.0/16 | 65.5k | ARIN | US | 4th Mar 2025 |
| 16.215.0.0/16 | 65.5k | ARIN | US | 24th Jul 2018 |
| 16.218.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.220.0.0/14 | 262k | ARIN | US | 18th May 1989 |
| 16.242.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.243.0.0/16 | 65.5k | ARIN | US | 24th Jul 2018 |
| 16.244.0.0/16 | 65.5k | ARIN | US | 24th Jul 2018 |
| 16.245.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.246.0.0/15 | 131k | ARIN | US | 18th May 1989 |
| 16.68.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.72.0.0/16 | 65.5k | ARIN | US | 18th May 1989 |
| 16.77.0.0/16 | 65.5k | ARIN | US | 11th Jul 2022 |
| 16.80.0.0/14 | 262k | ARIN | US | 18th May 1989 |
| 16.84.0.0/15 | 131k | ARIN | US | 18th May 1989 |
| 16.96.0.0/15 | 131k | ARIN | US | 18th May 1989 |
| 160.108.0.0/16 | 65.5k | ARIN | US | 18th Jun 2020 |
| 160.110.0.0/16 | 65.5k | ARIN | US | 26th May 1992 |
| 160.19.160.0/24 | 256 | ARIN | US | 20th Jun 2017 |
| 160.19.161.0/24 | 256 | ARIN | US | 10th Mar 2017 |
| 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 |
| 160.22.88.0/23 | 512 | APNIC | US | 6th Jun 2024 |
| 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 |
| 161.104.112.0/20 | 4.1k | RIPE NCC | US | 24th Jun 1992 |
| 161.104.128.0/19 | 8.2k | RIPE NCC | US | 24th 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 |