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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.185.237.0/24 | 256 | ARIN |  CA | 22nd Feb 1994 |
| 199.185.238.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.239.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.24.0/22 | 1k | ARIN | CA | 22nd Feb 1994 |
| 199.185.245.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.246.0/23 | 512 | ARIN | CA | 22nd Feb 1994 |
| 199.185.250.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.251.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.254.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.255.0/24 | 256 | ARIN | CA | 22nd May 1995 |
| 199.185.28.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.29.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.4.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.8.0/23 | 512 | ARIN | CA | 22nd Feb 1994 |
| 199.185.96.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.98.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.185.99.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.187.192.0/22 | 1k | ARIN | CA | 22nd Jul 2011 |
| 199.188.68.0/23 | 512 | ARIN | CA | 1st May 2012 |
| 199.188.71.0/24 | 256 | ARIN | CA | 1st May 2012 |
| 199.189.236.0/22 | 1k | ARIN | CA | 19th Aug 2011 |
| 199.189.4.0/23 | 512 | ARIN | CA | 8th Mar 1994 |
| 199.19.172.0/22 | 1k | ARIN | CA | 30th Sept 2025 |
| 199.195.114.0/23 | 512 | ARIN | CA | 31st Jul 2015 |
| 199.195.228.0/22 | 1k | ARIN | CA | 7th Jun 2012 |
| 199.195.232.0/22 | 1k | ARIN | CA | 3rd Oct 2025 |
| 199.198.140.0/22 | 1k | ARIN | CA | 25th Mar 1994 |
| 199.198.160.0/20 | 4.1k | ARIN | CA | 25th Mar 1994 |
| 199.198.176.0/21 | 2k | ARIN | CA | 25th Mar 1994 |
| 199.198.184.0/23 | 512 | ARIN | CA | 25th Mar 1994 |
| 199.198.186.0/24 | 256 | ARIN | CA | 13th Apr 2011 |
| 199.198.187.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.198.188.0/22 | 1k | ARIN | CA | 25th Mar 1994 |
| 199.198.192.0/20 | 4.1k | ARIN | CA | 25th Mar 1994 |
| 199.198.208.0/23 | 512 | ARIN | CA | 25th Mar 1994 |
| 199.198.218.0/24 | 256 | ARIN | CA | 14th Mar 1994 |
| 199.201.121.0/24 | 256 | ARIN | CA | 14th Aug 2019 |
| 199.201.226.0/23 | 512 | ARIN | CA | 5th May 1994 |
| 199.201.228.0/23 | 512 | ARIN | CA | 5th May 1994 |
| 199.202.102.0/23 | 512 | ARIN | CA | 18th Mar 1994 |
| 199.202.112.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.113.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.136.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.140.0/22 | 1k | ARIN | CA | 18th Mar 1994 |
| 199.202.149.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.150.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.151.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.152.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.155.0/24 | 256 | ARIN | CA | 18th Mar 1994 |
| 199.202.156.0/22 | 1k | ARIN | CA | 18th Mar 1994 |