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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.48.77.0/24 | 256 | ARIN |  US | 6th Feb 2026 |
| 192.48.81.0/24 | 256 | ARIN | US | 26th Jan 1989 |
| 192.48.84.0/22 | 1k | ARIN | US | 30th Nov 2012 |
| 192.48.88.0/22 | 1k | ARIN | US | 3rd Dec 2012 |
| 192.48.93.0/24 | 256 | ARIN | US | 30th Jan 1989 |
| 192.48.94.0/24 | 256 | ARIN | US | 31st Jan 1989 |
| 192.48.99.0/24 | 256 | ARIN | US | 2nd Feb 1989 |
| 192.5.10.0/24 | 256 | ARIN | US | 19th Jan 1983 |
| 192.5.100.0/24 | 256 | ARIN | US | 1st Nov 1985 |
| 192.5.103.0/24 | 256 | ARIN | US | 1st Nov 1989 |
| 192.5.105.0/24 | 256 | ARIN | US | 10th Aug 1984 |
| 192.5.107.0/24 | 256 | ARIN | US | 8th Oct 1984 |
| 192.5.108.0/24 | 256 | ARIN | US | 8th Oct 1984 |
| 192.5.111.0/24 | 256 | ARIN | US | 7th Jul 1988 |
| 192.5.112.0/24 | 256 | ARIN | US | 7th Jul 1988 |
| 192.5.13.0/24 | 256 | ARIN | US | 4th Apr 1983 |
| 192.5.133.0/24 | 256 | ARIN | US | 11th Nov 1985 |
| 192.5.135.0/24 | 256 | ARIN | US | 23rd Dec 1985 |
| 192.5.142.0/24 | 256 | RIPE NCC |  FR | 18th Mar 1986 |
| 192.5.144.0/24 | 256 | ARIN |  CA | 19th Mar 1986 |
| 192.5.145.0/24 | 256 | RIPE NCC |  DE | 1st Apr 1986 |
| 192.5.147.0/24 | 256 | ARIN | US | 2nd Jun 1997 |
| 192.5.149.0/24 | 256 | ARIN | US | 27th Mar 1986 |
| 192.5.150.0/24 | 256 | ARIN | US | 28th Mar 1986 |
| 192.5.151.0/24 | 256 | ARIN | US | 18th Feb 2014 |
| 192.5.152.0/23 | 512 | ARIN | US | 6th Mar 1991 |
| 192.5.156.0/24 | 256 | ARIN | US | 6th Mar 1991 |
| 192.5.164.0/24 | 256 | ARIN | US | 10th Apr 1986 |
| 192.5.165.0/24 | 256 | ARIN | US | 17th Apr 1986 |
| 192.5.167.0/24 | 256 | ARIN | US | 21st Apr 1986 |
| 192.5.168.0/24 | 256 | ARIN | US | 21st Apr 1986 |
| 192.5.169.0/24 | 256 | ARIN | US | 21st Apr 1986 |
| 192.5.192.0/21 | 2k | ARIN | US | 21st Apr 1986 |
| 192.5.20.0/24 | 256 | ARIN | US | 6th Jul 1983 |
| 192.5.202.0/24 | 256 | ARIN | US | 24th Apr 1986 |
| 192.5.204.0/24 | 256 | ARIN | CA | 15th May 1986 |
| 192.5.205.0/24 | 256 | ARIN | CA | 22nd May 1986 |
| 192.5.214.0/24 | 256 | ARIN | US | 9th Jun 1986 |
| 192.5.217.0/24 | 256 | ARIN | US | 2nd May 1990 |
| 192.5.220.0/24 | 256 | ARIN | US | 30th Jun 1986 |
| 192.5.223.0/24 | 256 | ARIN | US | 30th Jun 1986 |
| 192.5.224.0/24 | 256 | ARIN | US | 8th Jul 1986 |
| 192.5.225.0/24 | 256 | ARIN | US | 9th Jul 1986 |
| 192.5.226.0/23 | 512 | ARIN | US | 9th Jul 1986 |
| 192.5.228.0/22 | 1k | ARIN | US | 9th Jul 1986 |
| 192.5.232.0/22 | 1k | ARIN | US | 9th Jul 1986 |
| 192.5.236.0/24 | 256 | ARIN | US | 9th Jul 1986 |
| 192.5.237.0/24 | 256 | ARIN | US | 11th Aug 1988 |
| 192.5.238.0/24 | 256 | ARIN | US | 31st Mar 1989 |
| 192.5.239.0/24 | 256 | RIPE NCC |  GB | 3rd Apr 1989 |