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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 204.107.65.0/24 | 256 | ARIN |  US | 28th Sept 1994 |
| 204.107.66.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.107.67.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.107.68.0/24 | 256 | ARIN | US | 29th Sept 1994 |
| 204.107.70.0/24 | 256 | ARIN | US | 29th Sept 1994 |
| 204.107.71.0/24 | 256 | ARIN | US | 29th Sept 1994 |
| 204.107.72.0/24 | 256 | ARIN | US | 29th Sept 1994 |
| 204.107.74.0/24 | 256 | ARIN | US | 29th Sept 1994 |
| 204.107.75.0/24 | 256 | ARIN | US | 16th Jun 2011 |
| 204.107.76.0/24 | 256 | ARIN | US | 3rd Oct 1994 |
| 204.107.77.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.107.79.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.107.80.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.107.83.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.107.84.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.107.87.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 204.107.88.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 204.107.91.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 204.107.92.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 204.107.94.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.107.96.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.107.97.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.107.98.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.107.99.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.108.12.0/22 | 1k | ARIN | US | 15th Jan 2009 |
| 204.108.166.0/23 | 512 | ARIN | US | 6th Oct 1994 |
| 204.108.24.0/23 | 512 | ARIN | US | 28th Jul 1994 |
| 204.109.128.0/17 | 32.8k | ARIN | US | 4th Nov 1994 |
| 204.109.13.0/24 | 256 | ARIN | US | 7th Jul 2011 |
| 204.11.124.0/22 | 1k | ARIN | US | 18th Feb 2005 |
| 204.11.192.0/22 | 1k | ARIN | US | 10th Mar 2005 |
| 204.11.196.0/22 | 1k | ARIN | US | 14th Mar 2005 |
| 204.11.216.0/23 | 512 | ARIN | US | 17th Mar 2005 |
| 204.11.8.0/21 | 2k | ARIN |  CA | 15th Sept 2022 |
| 204.110.128.0/20 | 4.1k | ARIN | US | 5th Oct 1994 |
| 204.110.144.0/20 | 4.1k | ARIN | US | 11th Oct 1994 |
| 204.110.176.0/21 | 2k | ARIN | US | 19th Oct 1994 |
| 204.110.184.0/23 | 512 | ARIN | US | 19th Oct 1994 |
| 204.110.240.0/20 | 4.1k | ARIN | US | 18th Nov 1994 |
| 204.110.64.0/20 | 4.1k | ARIN | US | 19th Sept 1994 |
| 204.110.8.0/21 | 2k | APNIC |  HK | 16th Feb 2023 |
| 204.110.80.0/20 | 4.1k | ARIN | US | 23rd Sept 1994 |
| 204.114.10.0/23 | 512 | ARIN | US | 11th May 2011 |
| 204.114.16.0/21 | 2k | ARIN | US | 15th Sept 1994 |
| 204.114.64.0/18 | 16.4k | ARIN | US | 22nd Sept 1994 |
| 204.115.100.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.115.112.0/22 | 1k | ARIN | US | 30th Sept 1994 |
| 204.115.116.0/24 | 256 | ARIN | US | 30th Sept 1994 |
| 204.115.118.0/23 | 512 | ARIN | US | 18th May 2011 |
| 204.115.12.0/23 | 512 | ARIN | US | 19th Sept 1994 |