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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,221 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.91.180.0/24 | 256 | ARIN |  US | 17th Jan 1991 |
| 192.91.181.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.182.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.183.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.185.0/24 | 256 | APNIC |  AU | 17th Jan 1991 |
| 192.91.187.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.188.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.189.0/24 | 256 | RIPE NCC |  NO | 18th Jan 1991 |
| 192.91.190.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.192.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.193.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.194.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.195.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.196.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.197.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.200.0/24 | 256 | AFRINIC |  CI | 28th Feb 2020 |
| 192.91.201.0/24 | 256 | RIPE NCC |  GB | 18th Jan 1991 |
| 192.91.202.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.203.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.206.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.207.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.208.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.209.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.210.0/24 | 256 | ARIN |  CA | 18th Jan 1991 |
| 192.91.211.0/24 | 256 | RIPE NCC | GB | 18th Jan 1991 |
| 192.91.212.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.213.0/24 | 256 | APNIC | AU | 14th Feb 2011 |
| 192.91.248.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.251.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.252.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.61.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.65.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.67.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.68.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.69.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.70.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.71.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.72.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.73.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.74.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.76.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.77.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.78.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.79.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.80.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.81.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.82.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.83.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.84.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.85.0/24 | 256 | ARIN | US | 4th Jan 1991 |