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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
27,019 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.94.51.0/24 | 256 | ARIN |  US | 15th Feb 1991 |
| 192.94.52.0/24 | 256 | ARIN | US | 15th Feb 1991 |
| 192.94.53.0/24 | 256 | ARIN | US | 14th Feb 1991 |
| 192.94.55.0/24 | 256 | ARIN | US | 15th Feb 1991 |
| 192.94.56.0/24 | 256 | ARIN | US | 15th Feb 1991 |
| 192.94.59.0/24 | 256 | ARIN | US | 15th Feb 1991 |
| 192.94.6.0/24 | 256 | ARIN | US | 7th Feb 1991 |
| 192.94.60.0/24 | 256 | ARIN | US | 15th Feb 1991 |
| 192.94.65.0/24 | 256 | ARIN | US | 21st Feb 1991 |
| 192.94.69.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.7.0/24 | 256 | ARIN | US | 7th Feb 1991 |
| 192.94.75.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.77.0/24 | 256 | ARIN | US | 18th Nov 2019 |
| 192.94.78.0/24 | 256 | RIPE NCC | US | 12th Nov 2019 |
| 192.94.79.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.8.0/24 | 256 | ARIN | US | 7th Feb 1991 |
| 192.94.80.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.81.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.82.0/23 | 512 | ARIN | US | 22nd Feb 1991 |
| 192.94.84.0/22 | 1k | ARIN | US | 22nd Feb 1991 |
| 192.94.88.0/22 | 1k | ARIN | US | 22nd Feb 1991 |
| 192.94.9.0/24 | 256 | ARIN | US | 7th Feb 1991 |
| 192.94.94.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.95.0/24 | 256 | ARIN | US | 22nd Feb 1991 |
| 192.94.96.0/22 | 1k | ARIN | US | 22nd Feb 1991 |
| 192.96.135.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 192.96.160.0/22 | 1k | ARIN | US | 11th Jan 2013 |
| 192.96.23.0/24 | 256 | ARIN | US | 12th Feb 2015 |
| 192.96.36.0/24 | 256 | ARIN | US | 17th Feb 2015 |
| 192.96.59.0/24 | 256 | ARIN | US | 18th Feb 2015 |
| 192.97.0.0/16 | 65.5k | ARIN | US | 5th Mar 1991 |
| 193.0.129.0/24 | 256 | RIPE NCC | US | 12th Nov 2019 |
| 193.0.184.0/24 | 256 | RIPE NCC | US | 12th Nov 2019 |
| 193.0.212.0/24 | 256 | RIPE NCC | US | 12th Nov 2019 |
| 193.0.249.0/24 | 256 | RIPE NCC | US | 15th Aug 2002 |
| 193.104.126.0/24 | 256 | RIPE NCC | US | 17th Aug 2026 |
| 193.105.173.0/24 | 256 | RIPE NCC | US | 6th Aug 2010 |
| 193.105.177.0/24 | 256 | RIPE NCC | US | 15th Nov 2019 |
| 193.110.138.0/24 | 256 | RIPE NCC | US | 14th Jan 2002 |
| 193.110.81.0/24 | 256 | RIPE NCC | US | 11th Oct 2021 |
| 193.141.140.0/23 | 512 | RIPE NCC | US | 1st Sept 1993 |
| 193.187.1.0/24 | 256 | ARIN | US | 18th Jan 2022 |
| 193.194.158.0/24 | 256 | RIPE NCC | US | 29th Jul 1999 |
| 193.200.177.0/24 | 256 | RIPE NCC | US | 15th May 2007 |
| 193.200.184.0/24 | 256 | RIPE NCC | US | 18th May 2007 |
| 193.201.147.224/27 | 32 | RIPE NCC | US | 29th Jun 2004 |
| 193.201.150.0/26 | 64 | RIPE NCC | US | 29th Jun 2004 |
| 193.201.56.0/22 | 1k | RIPE NCC | US | 9th May 2018 |
| 193.227.227.0/24 | 256 | RIPE NCC | US | 17th Jul 2026 |
| 193.23.120.0/24 | 256 | RIPE NCC | US | 29th Jun 2004 |