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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.147.186.0/24 | 256 | ARIN |  US | 16th Feb 1992 |
| 192.147.187.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.188.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.189.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.190.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.191.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.192.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.193.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.194.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.195.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.196.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.197.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.198.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.199.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.200.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.201.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.202.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.203.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.204.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.205.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.206.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.207.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.208.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.209.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.21.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.211.0/24 | 256 | ARIN | US | 17th Feb 1992 |
| 192.147.212.0/24 | 256 | RIPE NCC |  GB | 17th Feb 1992 |
| 192.147.214.0/24 | 256 | ARIN | US | 17th Feb 1992 |
| 192.147.215.0/24 | 256 | RIPE NCC |  FI | 17th Feb 1992 |
| 192.147.216.0/24 | 256 | RIPE NCC | FI | 17th Feb 1992 |
| 192.147.217.0/24 | 256 | RIPE NCC | GB | 17th Feb 1992 |
| 192.147.219.0/24 | 256 | RIPE NCC | GB | 18th Feb 1992 |
| 192.147.22.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.225.0/24 | 256 | ARIN | US | 19th Feb 1992 |
| 192.147.226.0/24 | 256 | ARIN | US | 19th Feb 1992 |
| 192.147.227.0/24 | 256 | ARIN | US | 19th Feb 1992 |
| 192.147.228.0/24 | 256 | RIPE NCC | GB | 19th Feb 1992 |
| 192.147.229.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.147.23.0/24 | 256 | RIPE NCC | GB | 10th Feb 1992 |
| 192.147.230.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.147.233.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.147.234.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.147.235.0/24 | 256 | APNIC |  AU | 20th Feb 1992 |
| 192.147.236.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.147.238.0/24 | 256 | ARIN | US | 24th Feb 1992 |
| 192.147.24.0/24 | 256 | ARIN | US | 14th May 2015 |
| 192.147.240.0/24 | 256 | ARIN | US | 24th Feb 1992 |
| 192.147.244.0/24 | 256 | ARIN | US | 25th Feb 1992 |
| 192.147.245.0/24 | 256 | ARIN | US | 25th Feb 1992 |
| 192.147.246.0/24 | 256 | APNIC | AU | 25th Feb 1992 |