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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,195 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.58.150.0/24 | 256 | ARIN |  US | 20th Sept 1989 |
| 192.58.151.0/24 | 256 | ARIN | US | 25th Sept 1989 |
| 192.58.152.0/24 | 256 | ARIN | US | 25th Sept 1989 |
| 192.58.153.0/24 | 256 | ARIN | US | 25th Sept 1989 |
| 192.58.154.0/24 | 256 | ARIN | US | 25th Sept 1989 |
| 192.58.156.0/22 | 1k | ARIN | US | 3rd Oct 1989 |
| 192.58.160.0/20 | 4.1k | ARIN | US | 3rd Oct 1989 |
| 192.58.176.0/22 | 1k | ARIN | US | 3rd Oct 1989 |
| 192.58.184.0/21 | 2k | ARIN | US | 3rd Oct 1989 |
| 192.58.192.0/24 | 256 | ARIN | US | 3rd Oct 1989 |
| 192.58.194.0/24 | 256 | ARIN | US | 27th Nov 2017 |
| 192.58.195.0/24 | 256 | ARIN | US | 10th Oct 1989 |
| 192.58.197.0/24 | 256 | RIPE NCC |  SE | 11th Oct 1989 |
| 192.58.200.0/22 | 1k | ARIN | US | 10th Oct 1989 |
| 192.58.204.0/24 | 256 | ARIN | US | 11th Oct 1989 |
| 192.58.205.0/24 | 256 | ARIN | US | 11th Oct 1989 |
| 192.58.210.0/24 | 256 | ARIN | US | 11th Oct 1989 |
| 192.58.211.0/24 | 256 | ARIN | US | 10th Oct 1989 |
| 192.58.213.0/24 | 256 | ARIN |  CA | 19th Oct 1989 |
| 192.58.214.0/24 | 256 | ARIN | US | 30th Jul 2025 |
| 192.58.216.0/24 | 256 | ARIN | US | 17th Oct 1989 |
| 192.58.217.0/24 | 256 | ARIN | US | 17th Oct 1989 |
| 192.58.218.0/24 | 256 | RIPE NCC |  IT | 25th Oct 1989 |
| 192.58.220.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.222.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.223.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.228.0/23 | 512 | RIPE NCC |  NL | 25th Oct 1989 |
| 192.58.232.0/23 | 512 | ARIN | US | 25th Oct 1989 |
| 192.58.234.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.235.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.236.0/22 | 1k | ARIN | US | 25th Oct 1989 |
| 192.58.24.0/22 | 1k | ARIN | US | 29th Aug 1989 |
| 192.58.240.0/23 | 512 | ARIN | US | 25th Oct 1989 |
| 192.58.242.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.245.0/24 | 256 | ARIN | CA | 25th Oct 1989 |
| 192.58.249.0/24 | 256 | ARIN | US | 25th Oct 1989 |
| 192.58.254.0/24 | 256 | ARIN | US | 24th Oct 1989 |
| 192.58.28.0/24 | 256 | RIPE NCC |  LU | 5th Sept 1989 |
| 192.58.29.0/24 | 256 | RIPE NCC |  AE | 4th Jan 2012 |
| 192.58.40.0/24 | 256 | ARIN | US | 15th May 1989 |
| 192.59.0.0/16 | 65.5k | ARIN | US | 14th Sept 1989 |
| 192.6.0.0/23 | 512 | ARIN | US | 26th Aug 1983 |
| 192.6.10.0/24 | 256 | ARIN | US | 26th Aug 1983 |
| 192.6.100.0/23 | 512 | ARIN | US | 26th Aug 1983 |
| 192.6.102.0/24 | 256 | ARIN | US | 26th Aug 1983 |
| 192.6.103.0/24 | 256 | ARIN | US | 26th Aug 1983 |
| 192.6.104.0/23 | 512 | ARIN | US | 26th Aug 1983 |
| 192.6.106.0/24 | 256 | ARIN | US | 26th Aug 1983 |
| 192.6.108.0/23 | 512 | ARIN | US | 26th Aug 1983 |
| 192.6.11.0/24 | 256 | ARIN | US | 26th Aug 1983 |