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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
27,019 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 206.197.230.0/24 | 256 | ARIN |  US | 8th Sept 1995 |
| 206.197.232.0/24 | 256 | ARIN | US | 15th Sept 1995 |
| 206.197.233.0/24 | 256 | ARIN | US | 15th Sept 1995 |
| 206.197.234.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.235.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.237.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.239.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.24.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 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 |