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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,356 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 206.197.240.0/24 | 256 | ARIN |  US | 19th Sept 1995 |
| 206.197.242.0/24 | 256 | ARIN | US | 26th Sept 1995 |
| 206.197.243.0/24 | 256 | ARIN | US | 25th Oct 1995 |
| 206.197.245.0/24 | 256 | ARIN | US | 26th Oct 1995 |
| 206.197.246.0/24 | 256 | ARIN | US | 27th Oct 1995 |
| 206.197.247.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 206.197.248.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 206.197.249.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 206.197.250.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 206.197.252.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 206.197.253.0/24 | 256 | ARIN | US | 2nd Nov 1995 |
| 206.197.254.0/24 | 256 | ARIN | US | 2nd Nov 1995 |
| 206.197.255.0/24 | 256 | ARIN | US | 1st Sept 1995 |
| 206.197.27.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.28.0/24 | 256 | ARIN | US | 20th Jun 1995 |
| 206.197.29.0/24 | 256 | ARIN | US | 20th Jun 1995 |
| 206.197.3.0/24 | 256 | ARIN | US | 14th Jun 1995 |
| 206.197.32.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.33.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.35.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.36.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.37.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.38.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.39.0/24 | 256 | ARIN | US | 22nd Jun 1995 |
| 206.197.4.0/24 | 256 | ARIN | US | 14th Jun 1995 |
| 206.197.42.0/24 | 256 | ARIN | US | 23rd Jun 1995 |
| 206.197.43.0/24 | 256 | ARIN | US | 27th Jun 1995 |
| 206.197.45.0/24 | 256 | ARIN | US | 27th Jun 1995 |
| 206.197.46.0/24 | 256 | ARIN | US | 27th Jun 1995 |
| 206.197.48.0/24 | 256 | ARIN | US | 27th Jun 1995 |
| 206.197.51.0/24 | 256 | ARIN | US | 29th Jun 1995 |
| 206.197.52.0/24 | 256 | ARIN | US | 6th Jul 2026 |
| 206.197.53.0/24 | 256 | ARIN | US | 29th Jun 1995 |
| 206.197.54.0/24 | 256 | ARIN | US | 24th Aug 2026 |
| 206.197.55.0/24 | 256 | ARIN | US | 29th Jun 1995 |
| 206.197.56.0/24 | 256 | ARIN | US | 29th Jun 1995 |
| 206.197.57.0/24 | 256 | ARIN | US | 30th Jun 1995 |
| 206.197.6.0/24 | 256 | ARIN | US | 14th Jun 1995 |
| 206.197.64.0/24 | 256 | ARIN | US | 3rd Jul 1995 |
| 206.197.65.0/24 | 256 | ARIN | US | 3rd Jul 1995 |
| 206.197.66.0/24 | 256 | ARIN | US | 3rd Jul 1995 |
| 206.197.67.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.68.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.70.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.71.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.72.0/24 | 256 | ARIN | US | 10th Jul 1995 |
| 206.197.73.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.75.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.77.0/24 | 256 | ARIN | US | 6th Jul 1995 |
| 206.197.78.0/24 | 256 | ARIN | US | 10th Jul 1995 |