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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,221 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.88.75.0/24 | 256 | ARIN |  US | 12th Dec 1990 |
| 192.88.76.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.77.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.79.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.8.0/24 | 256 | ARIN | US | 29th Nov 1990 |
| 192.88.81.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.82.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.84.0/24 | 256 | RIPE NCC |  GB | 12th Dec 1990 |
| 192.88.85.0/24 | 256 | APNIC |  NZ | 26th Aug 2010 |
| 192.88.86.0/24 | 256 | RIPE NCC |  FI | 22nd Feb 1994 |
| 192.88.88.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.91.0/24 | 256 | ARIN | US | 12th Dec 1990 |
| 192.88.96.0/24 | 256 | ARIN | US | 26th Jan 2015 |
| 192.88.98.0/24 | 256 | RIPE NCC |  DE | 12th Dec 1990 |
| 192.91.100.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.102.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.103.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.104.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.105.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.106.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.107.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.110.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.111.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.112.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.113.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.114.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.115.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.116.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.117.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.118.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.119.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.120.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.121.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.122.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.123.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.124.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.125.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.126.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.127.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.128.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.129.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.130.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.131.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.136.0/24 | 256 | ARIN | US | 11th Jan 1991 |
| 192.91.140.0/24 | 256 | RIPE NCC |  LU | 15th Jan 1991 |
| 192.91.141.0/24 | 256 | RIPE NCC | LU | 15th Jan 1991 |
| 192.91.142.0/24 | 256 | ARIN | US | 15th Jan 1991 |
| 192.91.143.0/24 | 256 | ARIN | US | 15th Jan 1991 |
| 192.91.145.0/24 | 256 | ARIN | US | 16th Jan 1991 |
| 192.91.176.0/24 | 256 | ARIN | US | 17th Jan 1991 |