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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,461 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.135.227.0/24 | 256 | ARIN |  US | 25th May 1993 |
| 198.135.228.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.231.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.232.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.234.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.237.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.238.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.239.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.24.0/22 | 1k | ARIN | US | 7th Apr 1993 |
| 198.135.240.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.241.0/24 | 256 | ARIN | US | 3rd Oct 2025 |
| 198.135.242.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.243.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.244.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.246.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.247.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.248.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.251.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.253.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.254.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.255.0/24 | 256 | ARIN | US | 4th Jun 2013 |
| 198.135.64.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.65.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.66.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.67.0/24 | 256 | ARIN | US | 30th Sept 1996 |
| 198.135.68.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.69.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.71.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.135.72.0/24 | 256 | ARIN |  CA | 11th May 1993 |
| 198.135.73.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.135.75.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.135.76.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.135.77.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.136.0.0/21 | 2k | ARIN | US | 3rd Jun 1993 |
| 198.136.128.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.136.129.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.136.131.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.133.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.135.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.136.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.137.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.138.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.139.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.140.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.141.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.142.0/24 | 256 | ARIN | US | 27th May 1993 |
| 198.136.144.0/24 | 256 | ARIN | US | 28th May 1993 |
| 198.136.145.0/24 | 256 | ARIN | US | 28th May 1993 |
| 198.136.147.0/24 | 256 | ARIN | US | 28th May 1993 |
| 198.136.148.0/24 | 256 | ARIN | US | 1st Jun 1993 |