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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,041 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 164.152.218.0/23 | 512 | ARIN |  US | 12th Mar 1993 |
| 164.152.220.0/22 | 1k | ARIN | US | 12th Mar 1993 |
| 164.152.224.0/23 | 512 | ARIN | US | 12th Mar 1993 |
| 164.152.226.0/24 | 256 | ARIN | US | 12th Mar 1993 |
| 164.152.4.0/23 | 512 | ARIN | US | 12th Mar 1993 |
| 164.152.69.0/24 | 256 | ARIN | US | 12th Mar 1993 |
| 164.152.70.0/23 | 512 | ARIN | US | 12th Mar 1993 |
| 164.152.72.0/21 | 2k | ARIN | US | 12th Mar 1993 |
| 164.152.8.0/21 | 2k | ARIN | US | 17th Nov 2022 |
| 164.152.80.0/20 | 4.1k | ARIN | US | 12th Mar 1993 |
| 164.153.144.0/20 | 4.1k | ARIN | US | 14th Feb 2019 |
| 164.153.24.0/22 | 1k | RIPE NCC |  GB | 14th Feb 2019 |
| 164.153.64.0/18 | 16.4k | ARIN | US | 13th Jul 2020 |
| 164.160.100.0/22 | 1k | AFRINIC |  CI | 28th Feb 2020 |
| 164.160.132.0/22 | 1k | AFRINIC |  GH | 9th Aug 2016 |
| 164.160.20.0/22 | 1k | AFRINIC |  ZA | 20th May 2016 |
| 164.160.224.0/20 | 4.1k | AFRINIC |  RE | 9th May 2016 |
| 164.160.60.0/22 | 1k | AFRINIC | ZA | 13th Jun 2016 |
| 164.160.92.0/22 | 1k | AFRINIC | ZA | 4th Jul 2016 |
| 164.177.184.0/21 | 2k | RIPE NCC | US | 21st Nov 2011 |
| 164.179.0.0/16 | 65.5k | ARIN | US | 16th Apr 1993 |
| 164.34.0.0/16 | 65.5k | RIPE NCC |  DE | 22nd Sept 1992 |
| 164.35.0.0/16 | 65.5k | RIPE NCC |  BE | 20th Oct 1992 |
| 164.37.112.0/20 | 4.1k | RIPE NCC |  SE | 31st Jan 1993 |
| 164.37.128.0/18 | 16.4k | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.32.0/22 | 1k | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.36.0/23 | 512 | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.40.0/24 | 256 | RIPE NCC |  IS | 31st Jan 1993 |
| 164.37.41.0/24 | 256 | RIPE NCC | GB | 31st Jan 1993 |
| 164.37.42.0/24 | 256 | RIPE NCC | DE | 31st Jan 1993 |
| 164.37.48.0/22 | 1k | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.52.0/22 | 1k | RIPE NCC | DE | 31st Jan 1993 |
| 164.37.56.0/22 | 1k | RIPE NCC |  DK | 31st Jan 1993 |
| 164.37.60.0/22 | 1k | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.64.0/21 | 2k | RIPE NCC | SE | 31st Jan 1993 |
| 164.37.80.0/20 | 4.1k | RIPE NCC | SE | 31st Jan 1993 |
| 164.40.224.0/21 | 2k | RIPE NCC |  BA | 18th Nov 2011 |
| 164.40.232.0/24 | 256 | RIPE NCC |  RU | 6th May 2026 |
| 164.40.233.0/24 | 256 | RIPE NCC |  IR | 7th May 2026 |
| 164.40.234.0/24 | 256 | RIPE NCC |  KZ | 11th May 2026 |
| 164.40.236.0/24 | 256 | RIPE NCC |  TR | 12th May 2026 |
| 164.40.238.0/24 | 256 | RIPE NCC |  AZ | 15th May 2026 |
| 164.40.239.0/24 | 256 | RIPE NCC |  FR | 15th May 2026 |
| 164.5.232.0/23 | 512 | RIPE NCC |  FI | 25th Sept 1992 |
| 164.5.234.0/23 | 512 | RIPE NCC | FI | 25th Sept 1992 |
| 164.5.236.0/22 | 1k | RIPE NCC | FI | 25th Sept 1992 |
| 164.55.0.0/17 | 32.8k | ARIN | US | 9th Dec 1992 |
| 164.55.128.0/18 | 16.4k | ARIN | US | 9th Dec 1992 |
| 164.55.192.0/19 | 8.2k | ARIN | US | 9th Dec 1992 |
| 164.56.0.0/16 | 65.5k | ARIN | US | 5th Dec 1992 |