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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.16.215.0/24 | 256 | ARIN |  CA | 21st Nov 1988 |
| 192.16.216.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.217.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.218.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.219.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.220.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.221.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.222.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.223.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.224.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.225.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.226.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.227.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.228.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.229.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.230.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.231.0/24 | 256 | ARIN | CA | 14th Mar 1991 |
| 192.16.232.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.233.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.234.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.235.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.236.0/24 | 256 | ARIN | CA | 29th Oct 1992 |
| 192.16.237.0/24 | 256 | ARIN | CA | 29th Oct 1992 |
| 192.16.238.0/24 | 256 | ARIN | CA | 29th Oct 1992 |
| 192.16.239.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.240.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.241.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.242.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.243.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.244.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.245.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.246.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.247.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.248.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.249.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.252.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.253.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.254.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.255.0/24 | 256 | ARIN | CA | 30th Dec 1991 |
| 192.16.64.0/21 | 2k | ARIN |  US | 5th Nov 2012 |
| 192.16.72.0/24 | 256 | ARIN | US | 27th Jun 1986 |
| 192.16.74.0/24 | 256 | ARIN | US | 27th Jun 1986 |
| 192.160.0.0/24 | 256 | ARIN | US | 9th Dec 2016 |
| 192.160.1.0/24 | 256 | ARIN | US | 20th Apr 1992 |
| 192.160.10.0/24 | 256 | RIPE NCC |  RU | 8th Nov 2023 |
| 192.160.101.0/24 | 256 | ARIN | US | 9th Jul 2015 |
| 192.160.104.0/24 | 256 | ARIN | US | 15th Apr 1993 |
| 192.160.105.0/24 | 256 | ARIN | US | 15th Apr 1993 |
| 192.160.106.0/24 | 256 | RIPE NCC |  NL | 15th Apr 1993 |
| 192.160.107.0/24 | 256 | ARIN | US | 15th Apr 1993 |