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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in Canada
3,775 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.151.248.0/23 | 512 | ARIN |  CA | 28th Feb 1995 |
| 205.151.48.0/23 | 512 | ARIN | CA | 21st Apr 1995 |
| 205.151.52.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.53.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.57.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.58.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.59.0/24 | 256 | ARIN | CA | 17th Jan 1997 |
| 205.151.60.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.8.0/21 | 2k | ARIN | CA | 28th Feb 1995 |
| 205.151.80.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.81.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.82.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.83.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.84.0/22 | 1k | ARIN | CA | 28th Feb 1995 |
| 205.151.88.0/21 | 2k | ARIN | CA | 28th Feb 1995 |
| 205.151.96.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.97.0/24 | 256 | ARIN | CA | 28th Feb 1995 |
| 205.151.98.0/23 | 512 | ARIN | CA | 28th Feb 1995 |
| 205.153.228.0/23 | 512 | ARIN | CA | 1st Jul 2025 |
| 205.159.169.0/24 | 256 | ARIN | CA | 18th Jan 2022 |
| 205.166.123.0/24 | 256 | ARIN | CA | 3rd Apr 2025 |
| 205.178.148.0/24 | 256 | ARIN | CA | 9th Apr 2021 |
| 205.189.100.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.101.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.104.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.106.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.108.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.109.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.110.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.111.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.118.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.12.0/22 | 1k | ARIN | CA | 22nd Mar 1995 |
| 205.189.120.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.122.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.123.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.124.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.125.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.126.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.128.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.130.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.131.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.132.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.133.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.136.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.137.0/24 | 256 | ARIN | CA | 29th May 1996 |
| 205.189.138.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.140.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.142.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.143.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.144.0/22 | 1k | ARIN | CA | 22nd Mar 1995 |