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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
27,019 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.56.36.0/24 | 256 | ARIN |  US | 27th Jun 1989 |
| 192.56.37.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.64.0/21 | 2k | ARIN | US | 27th Jun 1989 |
| 192.56.74.0/23 | 512 | ARIN | US | 27th Jun 1989 |
| 192.58.0.0/24 | 256 | ARIN | US | 23rd Sept 2014 |
| 192.58.102.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.103.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.104.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.105.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.106.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.109.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.111.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.116.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.117.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.119.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.121.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 192.58.124.0/24 | 256 | ARIN | US | 19th Sept 1989 |
| 192.58.131.0/24 | 256 | ARIN | US | 27th Oct 2014 |
| 192.58.148.0/24 | 256 | ARIN | US | 13th Oct 2014 |
| 192.58.149.0/24 | 256 | ARIN | US | 20th Sept 1989 |
| 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 |
| 192.58.200.0/22 | 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 |
| 192.58.214.0/24 | 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 |
| 192.58.220.0/24 | 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 |
| 192.58.232.0/23 | 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 |