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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.55.222.0/24 | 256 | ARIN |  US | 31st Aug 1989 |
| 192.55.223.0/24 | 256 | ARIN | US | 31st Aug 1989 |
| 192.55.224.0/24 | 256 | ARIN |  CA | 31st Aug 1989 |
| 192.55.227.0/24 | 256 | ARIN | US | 4th Sept 1989 |
| 192.55.229.0/24 | 256 | ARIN | US | 4th Sept 1989 |
| 192.55.230.0/24 | 256 | ARIN | US | 5th Sept 1989 |
| 192.55.233.0/24 | 256 | ARIN | US | 5th Sept 1989 |
| 192.55.234.0/24 | 256 | ARIN | US | 5th Sept 1989 |
| 192.55.237.0/24 | 256 | ARIN | US | 8th Sept 1989 |
| 192.55.238.0/24 | 256 | APNIC |  ID | 7th Jan 2026 |
| 192.55.242.0/23 | 512 | ARIN | US | 10th Oct 2014 |
| 192.55.46.0/23 | 512 | APNIC |  CN | 26th Jun 1989 |
| 192.55.68.0/22 | 1k | APNIC | CN | 26th Jun 1989 |
| 192.55.80.0/23 | 512 | ARIN | US | 26th Jun 1989 |
| 192.55.88.0/24 | 256 | ARIN | US | 10th Jul 1989 |
| 192.55.89.0/24 | 256 | RIPE NCC |  DE | 10th Jul 1989 |
| 192.55.92.0/24 | 256 | ARIN | US | 27th Jun 1990 |
| 192.55.93.0/24 | 256 | ARIN | US | 27th Jun 1990 |
| 192.55.94.0/24 | 256 | ARIN | US | 27th Jun 1990 |
| 192.55.96.0/24 | 256 | ARIN | US | 18th Sept 2014 |
| 192.55.97.0/24 | 256 | ARIN | US | 13th Jul 1989 |
| 192.56.20.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.22.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.23.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.24.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.26.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.27.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.32.0/22 | 1k | ARIN | US | 27th Jun 1989 |
| 192.56.36.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.37.0/24 | 256 | ARIN | US | 27th Jun 1989 |
| 192.56.64.0/21 | 2k | ARIN | US | 27th Jun 1989 |
| 192.56.74.0/23 | 512 | ARIN | US | 27th Jun 1989 |
| 192.58.0.0/24 | 256 | ARIN | US | 23rd Sept 2014 |
| 192.58.102.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.103.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.104.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.105.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.106.0/24 | 256 | ARIN | US | 14th Sept 1989 |
| 192.58.109.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.111.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.116.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.117.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.119.0/24 | 256 | ARIN | US | 13th Sept 1989 |
| 192.58.121.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 192.58.124.0/24 | 256 | ARIN | US | 19th Sept 1989 |
| 192.58.131.0/24 | 256 | ARIN | US | 27th Oct 2014 |
| 192.58.133.0/24 | 256 | APNIC |  AU | 20th Sept 1989 |
| 192.58.136.0/24 | 256 | APNIC | AU | 20th Sept 1989 |
| 192.58.148.0/24 | 256 | ARIN | US | 13th Oct 2014 |
| 192.58.149.0/24 | 256 | ARIN | US | 20th Sept 1989 |