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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,195 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.75.161.0/24 | 256 | ARIN |  CA | 26th Mar 1990 |
| 192.75.162.0/24 | 256 | ARIN | CA | 23rd May 1994 |
| 192.75.163.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.164.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.166.0/24 | 256 | ARIN | CA | 31st Jul 1991 |
| 192.75.167.0/24 | 256 | ARIN | CA | 31st Jul 1991 |
| 192.75.168.0/24 | 256 | ARIN | CA | 31st Jul 1991 |
| 192.75.169.0/24 | 256 | ARIN | CA | 31st Jul 1991 |
| 192.75.170.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.173.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.176.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.177.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.178.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.179.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.180.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.181.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.182.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.183.0/24 | 256 | ARIN | CA | 26th Mar 1990 |
| 192.75.186.0/24 | 256 | ARIN | CA | 28th Jan 1992 |
| 192.75.189.0/24 | 256 | ARIN | CA | 23rd Jul 1992 |
| 192.75.19.0/24 | 256 | ARIN |  US | 21st Sept 1990 |
| 192.75.190.0/24 | 256 | ARIN | CA | 12th Dec 2014 |
| 192.75.196.0/23 | 512 | ARIN | US | 13th Jan 2026 |
| 192.75.198.0/24 | 256 | ARIN | US | 28th Apr 1995 |
| 192.75.2.0/24 | 256 | ARIN | CA | 8th Aug 1990 |
| 192.75.20.0/24 | 256 | ARIN | CA | 11th Oct 1990 |
| 192.75.208.0/24 | 256 | ARIN | CA | 18th Dec 1991 |
| 192.75.21.0/24 | 256 | ARIN | CA | 11th Oct 1990 |
| 192.75.210.0/24 | 256 | ARIN | CA | 20th Apr 1993 |
| 192.75.212.0/24 | 256 | ARIN | CA | 2nd Jun 1992 |
| 192.75.22.0/24 | 256 | ARIN | CA | 11th Oct 1990 |
| 192.75.230.0/24 | 256 | ARIN | CA | 18th Dec 1991 |
| 192.75.231.0/24 | 256 | ARIN | CA | 18th Dec 1991 |
| 192.75.232.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.75.233.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.75.234.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.75.235.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.75.236.0/24 | 256 | AFRINIC |  CI | 28th Feb 2020 |
| 192.75.248.0/24 | 256 | ARIN | CA | 6th Jan 1992 |
| 192.75.249.0/24 | 256 | ARIN | CA | 6th Jan 1992 |
| 192.75.25.0/24 | 256 | ARIN | CA | 12th Nov 1990 |
| 192.75.250.0/24 | 256 | ARIN | CA | 6th Jan 1992 |
| 192.75.251.0/24 | 256 | ARIN | CA | 6th Jan 1992 |
| 192.75.252.0/24 | 256 | ARIN | CA | 6th Jan 1992 |
| 192.75.27.0/24 | 256 | ARIN | CA | 30th Nov 1990 |
| 192.75.28.0/24 | 256 | ARIN | CA | 30th Nov 1990 |
| 192.75.29.0/24 | 256 | ARIN | CA | 30th Nov 1990 |
| 192.75.3.0/24 | 256 | ARIN | CA | 8th Aug 1990 |
| 192.75.30.0/24 | 256 | ARIN | CA | 30th Nov 1990 |
| 192.75.31.0/24 | 256 | ARIN | CA | 30th Nov 1990 |