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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,458 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.138.62.0/24 | 256 | ARIN |  CA | 30th Aug 1994 |
| 204.138.63.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.64.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.65.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.66.0/24 | 256 | ARIN | CA | 1st Jan 1995 |
| 204.138.67.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.69.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.70.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.73.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.8.0/21 | 2k | ARIN | CA | 30th Aug 1994 |
| 204.138.88.0/23 | 512 | ARIN | CA | 30th Aug 1994 |
| 204.138.90.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.91.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.92.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.93.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.96.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 204.138.97.0/24 | 256 | ARIN |  US | 30th Aug 1994 |
| 204.138.98.0/24 | 256 | ARIN | US | 30th Aug 1994 |
| 204.139.128.0/17 | 32.8k | ARIN | US | 28th Nov 1994 |
| 204.139.16.0/20 | 4.1k | ARIN | US | 1st Sept 1994 |
| 204.14.168.0/21 | 2k | ARIN | US | 6th Jul 2005 |
| 204.14.204.0/22 | 1k | ARIN | US | 3rd Oct 2024 |
| 204.14.216.0/21 | 2k | ARIN | US | 21st Jul 2005 |
| 204.140.0.0/20 | 4.1k | ARIN | US | 12th Sept 1994 |
| 204.144.100.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.101.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.102.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.103.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.105.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.107.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.108.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.109.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.110.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.111.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.112.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.115.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.116.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.117.0/24 | 256 | ARIN | US | 5th Jan 1995 |
| 204.144.118.0/23 | 512 | ARIN | US | 18th Jan 2011 |
| 204.144.56.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 204.144.64.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.65.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.66.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.67.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.68.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.70.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.71.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.72.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.73.0/24 | 256 | ARIN | US | 4th Jan 1995 |
| 204.144.75.0/24 | 256 | ARIN | US | 4th Jan 1995 |