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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
27,034 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.248.212.0/24 | 256 | ARIN |  US | 30th Sept 1994 |
| 199.248.213.0/24 | 256 | ARIN | US | 30th Sept 1994 |
| 199.248.214.0/24 | 256 | ARIN | US | 30th Sept 1994 |
| 199.248.215.0/24 | 256 | ARIN | US | 30th Sept 1994 |
| 199.248.216.0/24 | 256 | ARIN | US | 26th Jun 2024 |
| 199.248.217.0/24 | 256 | ARIN | US | 3rd Oct 1994 |
| 199.248.218.0/24 | 256 | ARIN | US | 3rd Oct 1994 |
| 199.248.219.0/24 | 256 | ARIN | US | 3rd Oct 1994 |
| 199.248.220.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 199.248.221.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 199.248.222.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 199.248.223.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 199.248.224.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 199.248.227.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.228.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.229.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.231.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.234.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.235.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.237.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.238.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 199.248.239.0/24 | 256 | ARIN | US | 2nd Jul 2025 |
| 199.248.24.0/22 | 1k | ARIN | US | 3rd May 1994 |
| 199.248.242.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.243.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.244.0/24 | 256 | ARIN | US | 25th Sept 2015 |
| 199.248.246.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.247.0/24 | 256 | ARIN | US | 7th Oct 1994 |
| 199.248.248.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.249.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.250.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.251.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.252.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.253.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.255.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 199.248.28.0/23 | 512 | ARIN | US | 3rd May 1994 |
| 199.248.30.0/24 | 256 | ARIN | US | 3rd May 1994 |
| 199.248.32.0/20 | 4.1k | ARIN | US | 29th Apr 1994 |
| 199.248.48.0/21 | 2k | ARIN | US | 29th Apr 1994 |
| 199.248.56.0/22 | 1k | ARIN | US | 29th Apr 1994 |
| 199.248.60.0/23 | 512 | ARIN | US | 29th Apr 1994 |
| 199.249.104.0/22 | 1k | ARIN | US | 20th May 1994 |
| 199.249.108.0/24 | 256 | ARIN | US | 20th May 1994 |
| 199.249.128.0/22 | 1k | ARIN | US | 25th May 1994 |
| 199.249.132.0/23 | 512 | ARIN | US | 25th May 1994 |
| 199.249.134.0/24 | 256 | ARIN | US | 26th May 1994 |
| 199.249.136.0/23 | 512 | ARIN | US | 27th May 1994 |
| 199.249.138.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.139.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.143.0/24 | 256 | ARIN | US | 27th May 1994 |