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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.139.143.0/24 | 256 | ARIN |  CA | 22nd Jun 1992 |
| 192.139.144.0/24 | 256 | ARIN | CA | 23rd Jun 1992 |
| 192.139.146.0/24 | 256 | ARIN | CA | 23rd Jun 1992 |
| 192.139.151.0/24 | 256 | ARIN | CA | 23rd Jul 1992 |
| 192.139.165.0/24 | 256 | ARIN | CA | 5th Feb 2024 |
| 192.139.176.0/21 | 2k | ARIN | CA | 13th Mar 2026 |
| 192.139.186.0/24 | 256 | ARIN | CA | 21st Oct 1992 |
| 192.139.197.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.199.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.2.0/24 | 256 | ARIN | CA | 10th Jan 1992 |
| 192.139.200.0/24 | 256 | ARIN | CA | 30th Dec 1992 |
| 192.139.201.0/24 | 256 | ARIN | CA | 2nd Dec 1992 |
| 192.139.203.0/24 | 256 | ARIN | CA | 2nd Dec 1992 |
| 192.139.204.0/24 | 256 | ARIN | CA | 2nd Dec 1992 |
| 192.139.206.0/24 | 256 | ARIN | CA | 12th Aug 1992 |
| 192.139.207.0/24 | 256 | ARIN | CA | 12th Aug 1992 |
| 192.139.208.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.209.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.210.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.211.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.212.0/24 | 256 | ARIN | CA | 10th Aug 1992 |
| 192.139.218.0/24 | 256 | ARIN | CA | 18th Aug 1992 |
| 192.139.22.0/24 | 256 | ARIN | CA | 19th Feb 1992 |
| 192.139.225.0/24 | 256 | ARIN | CA | 31st Aug 1992 |
| 192.139.226.0/24 | 256 | ARIN | CA | 31st Aug 1992 |
| 192.139.227.0/24 | 256 | ARIN | CA | 31st Aug 1992 |
| 192.139.228.0/24 | 256 | ARIN | CA | 2nd Sept 1992 |
| 192.139.229.0/24 | 256 | ARIN | CA | 2nd Sept 1992 |
| 192.139.23.0/24 | 256 | ARIN | CA | 18th Feb 1992 |
| 192.139.230.0/24 | 256 | ARIN | CA | 2nd Sept 1992 |
| 192.139.232.0/24 | 256 | ARIN | CA | 1st Oct 1992 |
| 192.139.234.0/24 | 256 | ARIN | CA | 1st Oct 1992 |
| 192.139.235.0/24 | 256 | ARIN | CA | 1st Oct 1992 |
| 192.139.236.0/24 | 256 | ARIN | CA | 1st Oct 1992 |
| 192.139.238.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.239.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.24.0/24 | 256 | ARIN | CA | 19th Feb 1992 |
| 192.139.240.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.241.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.242.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.243.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.244.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.246.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.247.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.248.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.249.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.25.0/24 | 256 | ARIN | CA | 23rd Jun 1993 |
| 192.139.250.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.251.0/24 | 256 | ARIN | CA | 2nd Oct 1992 |
| 192.139.252.0/24 | 256 | ARIN | CA | 26th Oct 1992 |