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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 167.150.104.0/22 | 1k | ARIN |  US | 2nd Aug 1993 |
| 167.150.110.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.112.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.116.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.118.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.12.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.121.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.122.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.124.0/22 | 1k | ARIN | US | 2nd Aug 1993 |
| 167.150.128.0/20 | 4.1k | ARIN | US | 2nd Aug 1993 |
| 167.150.14.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.144.0/22 | 1k | ARIN | US | 2nd Aug 1993 |
| 167.150.148.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.152.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.154.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.167.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.170.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.172.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.176.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.187.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.20.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.201.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.214.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.217.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.218.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.221.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.222.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.226.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.228.0/22 | 1k | ARIN | US | 2nd Aug 1993 |
| 167.150.23.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.232.0/23 | 512 | ARIN | US | 7th Nov 2025 |
| 167.150.234.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.240.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.248.0/21 | 2k | ARIN | US | 2nd Aug 1993 |
| 167.150.28.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.29.0/24 | 256 | ARIN | US | 28th Oct 2025 |
| 167.150.30.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.32.0/19 | 8.2k | ARIN | US | 2nd Aug 1993 |
| 167.150.72.0/21 | 2k | ARIN | US | 2nd Aug 1993 |
| 167.150.8.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.150.80.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.87.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.88.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 167.150.92.0/22 | 1k | ARIN | US | 2nd Aug 1993 |
| 167.150.98.0/23 | 512 | ARIN | US | 2nd Aug 1993 |
| 167.151.0.0/16 | 65.5k | ARIN | US | 2nd Aug 1993 |
| 167.152.0.0/16 | 65.5k | ARIN | US | 2nd Aug 1993 |
| 167.156.0.0/16 | 65.5k | ARIN | US | 6th Aug 1993 |
| 167.158.0.0/16 | 65.5k | ARIN | US | 9th Aug 1993 |
| 167.163.0.0/16 | 65.5k | ARIN | US | 11th Aug 1993 |