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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.136.62.0/24 | 256 | ARIN |  US | 6th Jan 1992 |
| 192.136.63.0/24 | 256 | ARIN | US | 6th Jan 1992 |
| 192.136.68.0/24 | 256 | ARIN | US | 7th Jan 1992 |
| 192.136.69.0/24 | 256 | ARIN | US | 7th Jan 1992 |
| 192.136.7.0/24 | 256 | RIPE NCC |  MT | 19th Dec 1991 |
| 192.136.71.0/24 | 256 | RIPE NCC |  FI | 16th Sept 2004 |
| 192.136.8.0/24 | 256 | ARIN | US | 4th Apr 1994 |
| 192.136.80.0/20 | 4.1k | RIPE NCC | FI | 16th Sept 2004 |
| 192.136.96.0/22 | 1k | RIPE NCC | FI | 16th Sept 2004 |
| 192.137.0.0/20 | 4.1k | ARIN | US | 20th May 1992 |
| 192.137.100.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.112.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.124.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.126.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.176.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.184.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.188.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.189.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.190.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.192.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.20.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.200.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.204.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.205.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.206.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.22.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.224.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.225.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.226.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.228.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.232.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.240.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.248.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.252.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.254.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.28.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.30.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.31.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.32.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.40.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.41.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.42.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.44.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.48.0/21 | 2k | ARIN | US | 20th May 1992 |
| 192.137.56.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.137.58.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.60.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.137.64.0/19 | 8.2k | ARIN | US | 20th May 1992 |
| 192.137.96.0/23 | 512 | ARIN | US | 20th May 1992 |
| 192.137.98.0/24 | 256 | ARIN | US | 20th May 1992 |