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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
27,007 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.207.188.0/24 | 256 | ARIN |  US | 10th Sept 1992 |
| 192.207.190.0/23 | 512 | ARIN | US | 10th Sept 1992 |
| 192.207.192.0/24 | 256 | ARIN | US | 10th Sept 1992 |
| 192.207.199.0/24 | 256 | ARIN | US | 10th Sept 1992 |
| 192.207.20.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.207.207.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.208.0/24 | 256 | ARIN | US | 23rd Dec 1992 |
| 192.207.209.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.210.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.211.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.212.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.217.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.218.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.219.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.22.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.207.220.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.221.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.222.0/24 | 256 | ARIN | US | 11th Sept 1992 |
| 192.207.223.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.224.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.227.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.228.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.229.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 192.207.23.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.207.231.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 192.207.232.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.233.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.235.0/24 | 256 | ARIN | US | 15th Sept 1992 |
| 192.207.237.0/24 | 256 | ARIN | US | 5th Dec 2022 |
| 192.207.239.0/24 | 256 | ARIN | US | 16th Sept 1992 |
| 192.207.24.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.207.243.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.207.245.0/24 | 256 | ARIN | US | 17th Sept 1992 |
| 192.207.249.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.207.250.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.207.251.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.207.253.0/24 | 256 | ARIN | US | 18th Sept 1992 |
| 192.207.26.0/24 | 256 | ARIN | US | 2nd Apr 2026 |
| 192.207.27.0/24 | 256 | ARIN | US | 17th Aug 1992 |
| 192.207.28.0/24 | 256 | ARIN | US | 17th Aug 1992 |
| 192.207.29.0/24 | 256 | ARIN | US | 17th Aug 1992 |
| 192.207.30.0/24 | 256 | ARIN | US | 17th Aug 1992 |
| 192.207.32.0/24 | 256 | ARIN | US | 18th Aug 1992 |
| 192.207.34.0/23 | 512 | ARIN | US | 24th Apr 2015 |
| 192.207.37.0/24 | 256 | ARIN | US | 18th Aug 1992 |
| 192.207.38.0/23 | 512 | ARIN | US | 18th Aug 1992 |
| 192.207.4.0/22 | 1k | ARIN | US | 12th Aug 1992 |
| 192.207.43.0/24 | 256 | ARIN | US | 18th Aug 1992 |
| 192.207.44.0/24 | 256 | ARIN | US | 18th Aug 1992 |
| 192.207.49.0/24 | 256 | ARIN | US | 24th Jul 2015 |