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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.206.188.0/24 | 256 | ARIN |  US | 9th Sept 1992 |
| 192.206.189.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.190.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.191.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.192.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.193.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.194.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.206.2.0/24 | 256 | ARIN |  CA | 1st Jul 2026 |
| 192.206.20.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.206.204.0/24 | 256 | ARIN | US | 23rd Jul 2015 |
| 192.206.205.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.208.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.209.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.210.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.213.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.214.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.215.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.216.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.206.217.0/24 | 256 | ARIN | CA | 18th Sept 1992 |
| 192.206.218.0/24 | 256 | ARIN | CA | 18th Sept 1992 |
| 192.206.22.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.206.222.0/24 | 256 | RIPE NCC |  IL | 29th Oct 1993 |
| 192.206.223.0/24 | 256 | RIPE NCC | IL | 18th Sept 1992 |
| 192.206.224.0/24 | 256 | RIPE NCC | IL | 18th Sept 1992 |
| 192.206.225.0/24 | 256 | RIPE NCC | IL | 18th Sept 1992 |
| 192.206.226.0/24 | 256 | RIPE NCC | IL | 18th Sept 1992 |
| 192.206.227.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.228.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.229.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.232.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.233.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.234.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.236.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.237.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.24.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.206.240.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.241.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.206.248.0/24 | 256 | ARIN | US | 25th Sept 1992 |
| 192.206.249.0/24 | 256 | ARIN | US | 24th Sept 1992 |
| 192.206.25.0/24 | 256 | ARIN | US | 6th Aug 1992 |
| 192.206.250.0/24 | 256 | ARIN | US | 24th Sept 1992 |
| 192.206.251.0/24 | 256 | ARIN | US | 24th Sept 1992 |
| 192.206.252.0/24 | 256 | ARIN | US | 24th Sept 1992 |
| 192.206.253.0/24 | 256 | ARIN | US | 25th Sept 1992 |
| 192.206.254.0/24 | 256 | ARIN | US | 25th Sept 1992 |
| 192.206.26.0/24 | 256 | ARIN | US | 6th Aug 1992 |
| 192.206.3.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 192.206.30.0/24 | 256 | ARIN | US | 6th Aug 1992 |
| 192.206.31.0/24 | 256 | ARIN | US | 6th Aug 1992 |
| 192.206.38.0/24 | 256 | ARIN | US | 6th Aug 1992 |