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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.150.110.0/24 | 256 | ARIN |  US | 11th Mar 1992 |
| 192.150.111.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.117.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.118.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.119.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.120.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.121.0/24 | 256 | ARIN | US | 20th Feb 1992 |
| 192.150.122.0/24 | 256 | ARIN | US | 11th Mar 1992 |
| 192.150.124.0/24 | 256 | RIPE NCC |  NO | 12th Mar 1992 |
| 192.150.125.0/24 | 256 | ARIN | US | 12th Mar 1992 |
| 192.150.126.0/24 | 256 | LACNIC |  GT | 12th Mar 1992 |
| 192.150.127.0/24 | 256 | ARIN | US | 13th Mar 1992 |
| 192.150.128.0/24 | 256 | ARIN | US | 13th Mar 1992 |
| 192.150.130.0/24 | 256 | APNIC |  AU | 13th Mar 1992 |
| 192.150.131.0/24 | 256 | APNIC | AU | 13th Mar 1992 |
| 192.150.132.0/24 | 256 | APNIC | AU | 13th Mar 1992 |
| 192.150.133.0/24 | 256 | APNIC | AU | 13th Mar 1992 |
| 192.150.134.0/24 | 256 | APNIC | AU | 13th Mar 1992 |
| 192.150.135.0/24 | 256 | APNIC | AU | 13th Mar 1992 |
| 192.150.136.0/24 | 256 | APNIC | AU | 7th Feb 2011 |
| 192.150.140.0/24 | 256 | RIPE NCC |  GB | 13th Mar 1992 |
| 192.150.141.0/24 | 256 | ARIN | US | 16th Mar 1992 |
| 192.150.145.0/24 | 256 | ARIN | US | 16th Mar 1992 |
| 192.150.146.0/24 | 256 | RIPE NCC |  IT | 16th Mar 1992 |
| 192.150.147.0/24 | 256 | ARIN | US | 16th Mar 1992 |
| 192.150.148.0/24 | 256 | ARIN | US | 16th Mar 1992 |
| 192.150.15.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 192.150.151.0/24 | 256 | ARIN | US | 18th Jun 2015 |
| 192.150.16.0/24 | 256 | APNIC |  IN | 25th Jun 1992 |
| 192.150.160.0/24 | 256 | ARIN | US | 4th Jun 2015 |
| 192.150.161.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.162.0/23 | 512 | ARIN | US | 17th Mar 1992 |
| 192.150.164.0/22 | 1k | ARIN | US | 17th Mar 1992 |
| 192.150.168.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.17.0/24 | 256 | ARIN | US | 25th Jun 1992 |
| 192.150.170.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.171.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.172.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.173.0/24 | 256 | ARIN | US | 17th Mar 1992 |
| 192.150.177.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.178.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.179.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.180.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.181.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.182.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.183.0/24 | 256 | RIPE NCC | GB | 17th Mar 1992 |
| 192.150.185.0/24 | 256 | ARIN |  CA | 31st Jul 2015 |
| 192.150.188.0/24 | 256 | RIPE NCC | NO | 18th Mar 1992 |
| 192.150.189.0/24 | 256 | RIPE NCC |  DE | 18th Mar 1992 |
| 192.150.190.0/24 | 256 | RIPE NCC | DE | 18th Mar 1992 |