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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,493 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.107.129.0/24 | 256 | ARIN |  US | 17th Oct 1994 |
| 204.107.131.0/24 | 256 | ARIN | US | 17th Oct 1994 |
| 204.107.132.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.133.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.137.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.138.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.14.0/23 | 512 | ARIN |  CA | 31st Mar 2021 |
| 204.107.140.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.142.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.143.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.144.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.148.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.149.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.107.150.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.151.0/24 | 256 | ARIN | US | 5th Jul 2011 |
| 204.107.152.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.155.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.156.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.157.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.158.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.159.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.160.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.161.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.162.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.163.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.164.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.165.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.166.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.167.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.169.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.170.0/24 | 256 | ARIN | US | 24th Oct 1994 |
| 204.107.171.0/24 | 256 | ARIN | US | 25th Oct 1994 |
| 204.107.172.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.174.0/24 | 256 | ARIN | US | 14th Oct 2022 |
| 204.107.176.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.177.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.179.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.180.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.181.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.182.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.183.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.185.0/24 | 256 | ARIN | US | 26th Oct 1994 |
| 204.107.186.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.187.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.188.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.189.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.190.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.193.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.194.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.195.0/24 | 256 | ARIN | US | 28th Oct 1994 |