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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,300 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 206.201.135.0/24 | 256 | ARIN | US | 2nd Aug 1995 |
| 206.201.96.0/20 | 4.1k | ARIN | US | 1st Aug 1995 |
| 206.203.192.0/18 | 16.4k | ARIN | US | 9th Aug 1995 |
| 206.206.32.0/19 | 8.2k | ARIN | US | 19th Jul 1995 |
| 206.207.72.0/23 | 512 | ARIN | US | 19th Jul 1995 |
| 206.207.75.0/24 | 256 | ARIN | US | 24th Jul 2025 |
| 206.207.76.0/22 | 1k | ARIN | US | 24th Jul 2025 |
| 206.208.104.0/21 | 2k | ARIN | US | 12th Sept 1995 |
| 206.208.144.0/21 | 2k | ARIN | US | 22nd Sept 1995 |
| 206.208.152.0/21 | 2k | ARIN | US | 22nd Sept 1995 |
| 206.208.160.0/21 | 2k | ARIN | US | 10th Oct 1995 |
| 206.208.192.0/21 | 2k | ARIN | US | 7th Nov 1995 |
| 206.208.240.0/21 | 2k | ARIN | US | 5th Dec 1995 |
| 206.208.248.0/21 | 2k | ARIN | US | 5th Dec 1995 |
| 206.208.40.0/21 | 2k | ARIN | US | 17th Aug 1995 |
| 206.208.48.0/21 | 2k | ARIN | US | 18th Aug 1995 |
| 206.208.72.0/21 | 2k | ARIN | US | 1st Sept 1995 |
| 206.208.8.0/21 | 2k | ARIN | US | 14th Aug 1995 |
| 206.208.80.0/21 | 2k | ARIN | US | 5th Sept 1995 |
| 206.209.100.0/22 | 1k | ARIN | US | 12th Jun 2007 |
| 206.209.104.0/23 | 512 | ARIN | US | 12th Jun 2007 |
| 206.209.106.0/24 | 256 | ARIN | US | 12th Jun 2007 |
| 206.209.107.0/24 | 256 | ARIN | US | 22nd Dec 2022 |
| 206.209.108.0/22 | 1k | ARIN | US | 12th Jun 2007 |
| 206.209.128.0/20 | 4.1k | ARIN | US | 11th Sept 1995 |
| 206.209.144.0/20 | 4.1k | ARIN | US | 11th Sept 1995 |
| 206.209.16.0/20 | 4.1k | ARIN | US | 22nd Aug 1995 |
| 206.209.176.0/20 | 4.1k | ARIN | US | 14th Sept 1995 |