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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 204.187.49.0/24 | 256 | ARIN |  CA | 7th Nov 1994 |
| 204.187.50.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.52.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.54.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.56.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.58.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.65.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.70.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.77.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.79.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.8.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.80.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.81.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.82.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.84.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.85.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.90.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.92.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.95.0/24 | 256 | ARIN | CA | 7th Nov 1994 |
| 204.187.96.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.187.98.0/23 | 512 | ARIN | CA | 7th Nov 1994 |
| 204.188.136.0/21 | 2k | ARIN |  US | 9th Nov 1994 |
| 204.189.0.0/16 | 65.5k | ARIN | US | 9th Nov 1994 |
| 204.19.1.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.100.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.102.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.104.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.105.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.106.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.108.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.109.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.110.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.111.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.112.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.113.0/24 | 256 | ARIN | CA | 6th Oct 1995 |
| 204.19.114.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.115.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.116.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.118.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.120.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.121.0/24 | 256 | ARIN | CA | 6th Oct 1995 |
| 204.19.123.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.124.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.126.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.13.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.130.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.132.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.135.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.136.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.139.0/24 | 256 | ARIN | CA | 6th Oct 1994 |