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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
30,479 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.90.120.0/23 | 512 | ARIN |  US | 10th Mar 1997 |
| 204.90.122.0/24 | 256 | ARIN | US | 10th Mar 1997 |
| 204.90.124.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.125.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.126.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.127.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.64.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.65.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.66.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.67.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.68.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.70.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.72.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.73.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.75.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.76.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.77.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.78.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.79.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.8.0/23 | 512 | ARIN | US | 18th Jul 1994 |
| 204.90.80.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.82.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.83.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.86.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.89.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.90.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.91.0/24 | 256 | ARIN | US | 4th Aug 2026 |
| 204.90.93.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.94.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.95.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.96.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.97.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.99.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.93.64.0/19 | 8.2k | ARIN | US | 29th Nov 2011 |
| 204.99.130.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.131.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.133.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.134.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.135.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.136.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.137.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.138.0/23 | 512 | ARIN | US | 12th Jul 1994 |
| 204.99.141.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.142.0/23 | 512 | ARIN | US | 12th Jul 1994 |
| 204.99.144.0/22 | 1k | ARIN | US | 12th Jul 1994 |
| 204.99.148.0/23 | 512 | ARIN | US | 12th Jul 1994 |
| 204.99.150.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.151.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 204.99.156.0/22 | 1k | ARIN | US | 12th Jul 1994 |
| 204.99.160.0/20 | 4.1k | ARIN | US | 12th Jul 1994 |