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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 205.233.179.0/24 | 256 | ARIN |  CA | 25th Apr 1995 |
| 205.233.180.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.182.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.233.184.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.185.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.188.0/22 | 1k | ARIN | CA | 25th Apr 1995 |
| 205.233.192.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.193.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.194.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.195.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.196.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.197.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.198.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.20.0/23 | 512 | ARIN | CA | 6th Dec 1995 |
| 205.233.200.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.202.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.203.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.204.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.205.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.206.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.211.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.213.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.214.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.215.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.216.0/24 | 256 | ARIN | CA | 10th Mar 2026 |
| 205.233.217.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.218.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.219.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.220.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.221.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.222.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.223.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.224.0/20 | 4.1k | ARIN | CA | 25th Apr 1995 |
| 205.233.240.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.241.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.242.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.248.0/22 | 1k | ARIN | CA | 25th Apr 1995 |
| 205.233.252.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.253.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.254.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.3.0/24 | 256 | ARIN | CA | 2nd Oct 1995 |
| 205.233.32.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.34.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.36.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.37.0/24 | 256 | ARIN | CA | 17th Nov 1995 |
| 205.233.38.0/24 | 256 | ARIN | CA | 6th Jul 2026 |
| 205.233.60.0/22 | 1k | ARIN | CA | 12th Dec 1995 |
| 205.233.65.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.66.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.67.0/24 | 256 | ARIN | CA | 31st Oct 1995 |