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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,149 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.166.16.0/21 | 2k | RIPE NCC |  DE | 7th May 1992 |
| 192.166.24.0/22 | 1k | RIPE NCC | DE | 7th May 1992 |
| 192.166.242.0/23 | 512 | RIPE NCC |  AT | 6th Jul 2018 |
| 192.166.253.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.254.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.28.0/22 | 1k | RIPE NCC | DE | 7th May 1992 |
| 192.166.36.0/24 | 256 | RIPE NCC |  IR | 6th Feb 2026 |
| 192.166.39.0/24 | 256 | RIPE NCC |  FR | 9th Feb 2026 |
| 192.166.49.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.50.0/23 | 512 | RIPE NCC | DE | 7th May 1992 |
| 192.166.52.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.53.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.54.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.55.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.80.0/24 | 256 | RIPE NCC | DE | 7th May 1992 |
| 192.166.88.0/21 | 2k | RIPE NCC | DE | 7th May 1992 |
| 192.169.16.0/24 | 256 | ARIN |  US | 12th May 1992 |
| 192.169.17.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.169.18.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.169.33.0/24 | 256 | APNIC |  PH | 12th May 1992 |
| 192.169.35.0/24 | 256 | APNIC |  SG | 12th May 1992 |
| 192.169.36.0/24 | 256 | APNIC | SG | 12th May 1992 |
| 192.169.39.0/24 | 256 | APNIC | SG | 12th May 1992 |
| 192.169.4.0/24 | 256 | ARIN |  CA | 3rd Oct 2022 |
| 192.169.40.0/24 | 256 | APNIC | SG | 12th May 1992 |
| 192.169.5.0/24 | 256 | ARIN | US | 13th Jul 2015 |
| 192.169.64.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.169.65.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.169.8.0/24 | 256 | ARIN | US | 8th May 1992 |
| 192.169.9.0/24 | 256 | ARIN | US | 8th May 1992 |
| 192.170.108.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.110.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.112.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.113.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.114.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.115.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.116.0/22 | 1k | ARIN | US | 6th May 1992 |
| 192.170.120.0/22 | 1k | ARIN | US | 6th May 1992 |
| 192.170.124.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.126.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.127.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.128.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.14.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.15.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.150.0/23 | 512 | ARIN | US | 29th Jul 2026 |
| 192.170.28.0/22 | 1k | ARIN | US | 6th May 1992 |
| 192.170.32.0/22 | 1k | ARIN | US | 6th May 1992 |
| 192.170.36.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.38.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.4.0/24 | 256 | ARIN | US | 6th May 1992 |