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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,283 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.112.183.0/24 | 256 | ARIN |  US | 5th Sept 1991 |
| 192.112.184.0/21 | 2k | ARIN | US | 5th Sept 1991 |
| 192.112.192.0/21 | 2k | ARIN | US | 5th Sept 1991 |
| 192.112.200.0/22 | 1k | ARIN | US | 5th Sept 1991 |
| 192.112.205.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.207.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.209.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.211.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.212.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.216.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.217.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.218.0/24 | 256 | ARIN | US | 17th Sept 1991 |
| 192.112.219.0/24 | 256 | ARIN | US | 18th Sept 1991 |
| 192.112.22.0/24 | 256 | ARIN | US | 21st Jun 1991 |
| 192.112.242.0/24 | 256 | ARIN | US | 23rd Sept 1991 |
| 192.112.246.0/24 | 256 | ARIN | US | 23rd Sept 1991 |
| 192.112.248.0/24 | 256 | ARIN | US | 23rd Sept 1991 |
| 192.112.249.0/24 | 256 | ARIN | US | 23rd Sept 1991 |
| 192.112.25.0/24 | 256 | ARIN | US | 21st Jun 1991 |
| 192.112.250.0/24 | 256 | ARIN | US | 25th Sept 1991 |
| 192.112.251.0/24 | 256 | ARIN | US | 25th Sept 1991 |
| 192.112.252.0/24 | 256 | ARIN | US | 25th Sept 1991 |
| 192.112.26.0/24 | 256 | ARIN | US | 18th Sept 2025 |
| 192.112.27.0/24 | 256 | ARIN | US | 25th Jun 2025 |
| 192.112.28.0/24 | 256 | ARIN | US | 26th Jun 1991 |
| 192.112.3.0/24 | 256 | ARIN | US | 21st Jun 1991 |
| 192.112.33.0/24 | 256 | ARIN | US | 16th Apr 2025 |
| 192.112.35.0/24 | 256 | ARIN | US | 14th Apr 2015 |
| 192.112.39.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.112.4.0/22 | 1k | ARIN | US | 21st Jun 1991 |
| 192.112.40.0/22 | 1k | ARIN | US | 1st Jul 1991 |
| 192.112.44.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.112.46.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.112.50.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.112.51.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.112.52.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.53.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.55.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.56.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.57.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.58.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.59.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.62.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.67.0/24 | 256 | ARIN | US | 30th Jul 1991 |
| 192.112.80.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.112.81.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.112.84.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.112.85.0/24 | 256 | ARIN | US | 7th Aug 1991 |
| 192.112.86.0/24 | 256 | ARIN | US | 7th Aug 1991 |
| 192.112.87.0/24 | 256 | ARIN | US | 7th Aug 1991 |