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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.104.88.0/21 | 2k | ARIN |  US | 16th May 1991 |
| 192.104.96.0/21 | 2k | ARIN | US | 16th May 1991 |
| 192.105.0.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.108.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.109.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.11.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.110.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.112.0/20 | 4.1k | ARIN | US | 26th Mar 1991 |
| 192.105.12.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.128.0/19 | 8.2k | ARIN | US | 26th Mar 1991 |
| 192.105.16.0/20 | 4.1k | ARIN | US | 26th Mar 1991 |
| 192.105.160.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.168.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.172.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.192.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.194.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.195.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.196.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.200.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.204.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.206.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.208.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.212.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.216.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.224.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.232.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.234.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.235.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.236.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.240.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.248.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.252.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.254.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.255.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.32.0/24 | 256 | ARIN | US | 22nd May 1991 |
| 192.105.33.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.34.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.36.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.37.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.38.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.40.0/21 | 2k | ARIN | US | 26th Mar 1991 |
| 192.105.48.0/20 | 4.1k | ARIN | US | 26th Mar 1991 |
| 192.105.64.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.66.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.67.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.68.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.72.0/23 | 512 | ARIN | US | 26th Mar 1991 |
| 192.105.74.0/24 | 256 | ARIN | US | 26th Mar 1991 |
| 192.105.76.0/22 | 1k | ARIN | US | 26th Mar 1991 |
| 192.105.8.0/23 | 512 | ARIN | US | 26th Mar 1991 |