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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.132.18.0/24 | 256 | ARIN |  US | 7th Nov 1991 |
| 192.132.19.0/24 | 256 | ARIN |  CA | 29th Mar 1992 |
| 192.132.20.0/24 | 256 | ARIN | US | 6th Nov 1991 |
| 192.132.204.0/24 | 256 | ARIN | US | 4th May 1992 |
| 192.132.207.0/24 | 256 | ARIN | US | 17th Aug 1993 |
| 192.132.21.0/24 | 256 | ARIN | US | 6th Nov 1991 |
| 192.132.210.0/24 | 256 | ARIN | US | 29th Jul 1994 |
| 192.132.211.0/24 | 256 | ARIN | US | 18th Nov 1991 |
| 192.132.213.0/24 | 256 | ARIN | US | 18th Nov 1991 |
| 192.132.214.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.215.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.216.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.22.0/24 | 256 | ARIN | US | 6th Nov 1991 |
| 192.132.220.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.224.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.226.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.23.0/24 | 256 | ARIN | US | 7th Nov 1991 |
| 192.132.231.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.232.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.233.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.234.0/24 | 256 | ARIN | US | 18th Nov 1991 |
| 192.132.238.0/24 | 256 | ARIN | US | 18th Nov 1991 |
| 192.132.239.0/24 | 256 | RIPE NCC |  GB | 18th Nov 1991 |
| 192.132.24.0/24 | 256 | ARIN | US | 7th Nov 1991 |
| 192.132.240.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.132.241.0/24 | 256 | ARIN | CA | 18th Nov 1991 |
| 192.132.242.0/24 | 256 | ARIN | US | 19th Nov 1991 |
| 192.132.244.0/24 | 256 | RIPE NCC |  IL | 19th Nov 1991 |
| 192.132.245.0/24 | 256 | RIPE NCC |  NL | 19th Nov 1991 |
| 192.132.246.0/24 | 256 | ARIN | US | 19th Nov 1991 |
| 192.132.248.0/22 | 1k | APNIC |  KR | 26th Nov 1991 |
| 192.132.25.0/24 | 256 | ARIN | US | 7th Nov 1991 |
| 192.132.252.0/24 | 256 | RIPE NCC |  CH | 20th Nov 1991 |
| 192.132.253.0/24 | 256 | APNIC |  AU | 20th Nov 1991 |
| 192.132.254.0/24 | 256 | ARIN | US | 20th Nov 1991 |
| 192.132.26.0/24 | 256 | ARIN | US | 7th Nov 1991 |
| 192.132.29.0/24 | 256 | ARIN | US | 7th Nov 1991 |
| 192.132.3.0/24 | 256 | ARIN | US | 1st Nov 1991 |
| 192.132.36.0/24 | 256 | ARIN | US | 8th Nov 1991 |
| 192.132.37.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.38.0/24 | 256 | ARIN | US | 8th Nov 1991 |
| 192.132.39.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.4.0/24 | 256 | ARIN | US | 4th Nov 1991 |
| 192.132.40.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.132.42.0/24 | 256 | ARIN | US | 12th Nov 1991 |
| 192.132.43.0/24 | 256 | ARIN | US | 12th Nov 1991 |
| 192.132.45.0/24 | 256 | ARIN | US | 12th Nov 1991 |
| 192.132.46.0/24 | 256 | ARIN | US | 12th Nov 1991 |
| 192.132.47.0/24 | 256 | ARIN | US | 12th Nov 1991 |
| 192.132.48.0/24 | 256 | ARIN | US | 12th Nov 1991 |