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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in Canada
3,819 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.236.181.0/24 | 256 | ARIN |  CA | 25th Apr 1995 |
| 205.236.182.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.185.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.186.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.188.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.189.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.19.0/24 | 256 | ARIN | CA | 9th Feb 1996 |
| 205.236.191.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.225.0/24 | 256 | ARIN | CA | 20th Oct 1995 |
| 205.236.227.0/24 | 256 | ARIN | CA | 20th Oct 1995 |
| 205.236.228.0/24 | 256 | ARIN | CA | 20th Oct 1995 |
| 205.236.229.0/24 | 256 | ARIN | CA | 14th May 1996 |
| 205.236.232.0/24 | 256 | ARIN | CA | 12th Apr 1996 |
| 205.236.233.0/24 | 256 | ARIN | CA | 3rd Oct 1995 |
| 205.236.235.0/24 | 256 | ARIN | CA | 28th Sept 1995 |
| 205.236.236.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.237.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.238.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.240.0/22 | 1k | ARIN | CA | 25th Apr 1995 |
| 205.236.244.0/24 | 256 | ARIN | CA | 28th Mar 2022 |
| 205.236.26.0/24 | 256 | ARIN | CA | 27th Nov 1995 |
| 205.236.28.0/23 | 512 | ARIN | CA | 22nd Nov 1995 |
| 205.236.30.0/24 | 256 | ARIN | CA | 22nd Nov 1995 |
| 205.236.32.0/23 | 512 | ARIN | CA | 10th Nov 1995 |
| 205.236.36.0/24 | 256 | ARIN | CA | 20th Nov 1995 |
| 205.236.37.0/24 | 256 | ARIN | CA | 6th Nov 1995 |
| 205.236.38.0/23 | 512 | ARIN | CA | 6th Nov 1995 |
| 205.236.40.0/24 | 256 | ARIN | CA | 7th Nov 1995 |
| 205.236.46.0/24 | 256 | ARIN | CA | 7th Nov 1995 |
| 205.236.47.0/24 | 256 | ARIN | CA | 27th Oct 1995 |
| 205.236.48.0/23 | 512 | ARIN | CA | 18th Oct 1995 |
| 205.236.50.0/24 | 256 | ARIN | CA | 23rd Oct 1995 |
| 205.236.52.0/24 | 256 | ARIN | CA | 23rd Oct 1995 |
| 205.236.53.0/24 | 256 | ARIN | CA | 19th Oct 1995 |
| 205.236.55.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.236.57.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.236.58.0/24 | 256 | ARIN | CA | 18th Jan 1996 |
| 205.236.59.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.236.60.0/22 | 1k | ARIN | CA | 2nd Oct 1995 |
| 205.236.64.0/22 | 1k | ARIN | CA | 2nd Oct 1995 |
| 205.236.68.0/23 | 512 | ARIN | CA | 2nd Oct 1995 |
| 205.236.70.0/24 | 256 | ARIN | CA | 16th Oct 1995 |
| 205.236.72.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.236.74.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.236.82.0/24 | 256 | ARIN | CA | 19th Sept 1995 |
| 205.236.83.0/24 | 256 | ARIN | CA | 19th Sept 1995 |
| 205.236.88.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.90.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.91.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.92.0/24 | 256 | ARIN | CA | 25th Apr 1995 |