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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
26,951 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 206.197.7.0/24 | 256 | ARIN | US | 5th Oct 2026 |
| 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 |
| 206.197.79.0/24 | 256 | ARIN | US | 10th Jul 1995 |
| 206.197.8.0/24 | 256 | ARIN | US | 15th Jun 1995 |
| 206.197.80.0/24 | 256 | ARIN | US | 10th Jul 1995 |
| 206.197.81.0/24 | 256 | ARIN | US | 12th Jul 1995 |
| 206.197.82.0/24 | 256 | ARIN | US | 12th Jul 1995 |
| 206.197.83.0/24 | 256 | ARIN | US | 12th Jul 1995 |
| 206.197.84.0/24 | 256 | ARIN | US | 13th Jul 1995 |
| 206.197.85.0/24 | 256 | ARIN | US | 14th Jul 1995 |
| 206.197.86.0/24 | 256 | ARIN | US | 14th Jul 1995 |
| 206.197.89.0/24 | 256 | ARIN | US | 18th Jul 1995 |
| 206.197.92.0/24 | 256 | ARIN | US | 18th Jul 1995 |
| 206.197.93.0/24 | 256 | ARIN | US | 18th Jul 1995 |
| 206.197.94.0/24 | 256 | ARIN | US | 18th Jul 1995 |
| 206.197.95.0/24 | 256 | ARIN | US | 19th Jul 1995 |
| 206.197.96.0/24 | 256 | ARIN | US | 19th Jul 1995 |
| 206.197.97.0/24 | 256 | ARIN | US | 19th Jul 1995 |
| 206.197.98.0/24 | 256 | ARIN | US | 19th Jul 1995 |
| 206.197.99.0/24 | 256 | ARIN | US | 19th Jul 1995 |
| 206.198.232.0/21 | 2k | ARIN | US | 10th Aug 2017 |