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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,201 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.245.133.0/24 | 256 | ARIN |  US | 5th Nov 1992 |
| 192.245.134.0/24 | 256 | ARIN | US | 5th Nov 1992 |
| 192.245.137.0/24 | 256 | ARIN | US | 5th Nov 1992 |
| 192.245.138.0/24 | 256 | ARIN | US | 5th Nov 1992 |
| 192.245.139.0/24 | 256 | ARIN | US | 5th Nov 1992 |
| 192.245.141.0/24 | 256 | ARIN | US | 6th Nov 1992 |
| 192.245.142.0/24 | 256 | ARIN | US | 6th Nov 1992 |
| 192.245.144.0/24 | 256 | ARIN | US | 6th Nov 1992 |
| 192.245.145.0/24 | 256 | ARIN | US | 6th Nov 1992 |
| 192.245.146.0/23 | 512 | ARIN | US | 6th Nov 1992 |
| 192.245.148.0/24 | 256 | AFRINIC |  DZ | 9th Nov 1992 |
| 192.245.149.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.150.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.151.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.152.0/24 | 256 | RIPE NCC |  UA | 9th Nov 1992 |
| 192.245.153.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.154.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.156.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.16.0/24 | 256 | ARIN | US | 27th Oct 1992 |
| 192.245.163.0/24 | 256 | ARIN | US | 9th Nov 1992 |
| 192.245.164.0/24 | 256 | ARIN | US | 27th Jan 1993 |
| 192.245.168.0/24 | 256 | ARIN | US | 27th Feb 2023 |
| 192.245.17.0/24 | 256 | ARIN | US | 27th Oct 1992 |
| 192.245.170.0/24 | 256 | ARIN | US | 17th Nov 1992 |
| 192.245.172.0/24 | 256 | ARIN |  CA | 18th Nov 1992 |
| 192.245.173.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.174.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.175.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.178.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.18.0/24 | 256 | ARIN | US | 12th Jul 1994 |
| 192.245.180.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.182.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.183.0/24 | 256 | ARIN | CA | 18th Nov 1992 |
| 192.245.184.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.187.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.188.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.189.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.190.0/24 | 256 | ARIN | US | 18th Nov 1992 |
| 192.245.191.0/24 | 256 | ARIN | US | 19th Nov 1992 |
| 192.245.2.0/24 | 256 | ARIN | US | 6th Aug 2015 |
| 192.245.200.0/22 | 1k | ARIN | US | 19th Nov 1992 |
| 192.245.204.0/23 | 512 | ARIN | US | 19th Nov 1992 |
| 192.245.206.0/24 | 256 | ARIN | US | 19th Nov 1992 |
| 192.245.207.0/24 | 256 | ARIN | US | 19th Nov 1992 |
| 192.245.209.0/24 | 256 | ARIN | US | 19th Nov 1992 |
| 192.245.218.0/24 | 256 | ARIN | US | 19th Nov 1992 |
| 192.245.220.0/24 | 256 | APNIC |  NZ | 24th Jan 2011 |
| 192.245.225.0/24 | 256 | RIPE NCC |  GB | 25th Nov 1992 |
| 192.245.226.0/24 | 256 | ARIN | US | 27th Nov 1992 |
| 192.245.227.0/24 | 256 | ARIN | US | 27th Nov 1992 |