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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,289 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.191.0.0/16 | 65.5k | ARIN |  US | 1st Jul 1992 |
| 192.195.101.0/24 | 256 | ARIN | US | 21st Jul 1992 |
| 192.195.104.0/24 | 256 | ARIN | US | 21st Jul 1992 |
| 192.195.107.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.195.108.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.195.11.0/24 | 256 | ARIN | US | 10th Jul 1992 |
| 192.195.113.0/24 | 256 | ARIN | US | 24th Jul 1992 |
| 192.195.114.0/23 | 512 | ARIN | US | 24th Jul 1992 |
| 192.195.119.0/24 | 256 | ARIN | US | 24th Jul 1992 |
| 192.195.120.0/21 | 2k | ARIN | US | 24th Jul 1992 |
| 192.195.128.0/22 | 1k | ARIN | US | 24th Jul 1992 |
| 192.195.132.0/23 | 512 | ARIN | US | 24th Jul 1992 |
| 192.195.149.0/24 | 256 | ARIN | US | 27th Jul 1992 |
| 192.195.15.0/24 | 256 | ARIN | US | 10th Jul 1992 |
| 192.195.150.0/24 | 256 | ARIN | US | 27th Jul 1992 |
| 192.195.156.0/22 | 1k | ARIN | US | 28th Jul 1992 |
| 192.195.16.0/22 | 1k | ARIN | US | 10th Jul 1992 |
| 192.195.160.0/22 | 1k | ARIN | US | 28th Jul 1992 |
| 192.195.164.0/23 | 512 | ARIN | US | 28th Jul 1992 |
| 192.195.166.0/24 | 256 | ARIN | US | 28th Jul 1992 |
| 192.195.167.0/24 | 256 | ARIN | US | 28th Jul 1992 |
| 192.195.168.0/24 | 256 | ARIN | US | 28th Jul 1992 |
| 192.195.169.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.195.171.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.195.172.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.195.174.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 192.195.175.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.195.178.0/23 | 512 | ARIN | US | 31st Jul 1992 |
| 192.195.180.0/23 | 512 | ARIN | US | 31st Jul 1992 |
| 192.195.182.0/24 | 256 | ARIN | US | 31st Jul 1992 |
| 192.195.187.0/24 | 256 | ARIN | US | 25th Nov 1995 |
| 192.195.188.0/24 | 256 | ARIN | US | 3rd Aug 1992 |
| 192.195.189.0/24 | 256 | ARIN | US | 3rd Aug 1992 |
| 192.195.190.0/24 | 256 | ARIN | US | 3rd Aug 1992 |
| 192.195.191.0/24 | 256 | ARIN | US | 3rd Aug 1992 |
| 192.195.192.0/23 | 512 | ARIN | US | 8th Jul 1997 |
| 192.195.194.0/24 | 256 | ARIN | US | 8th Jul 1997 |
| 192.195.199.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.20.0/23 | 512 | ARIN | US | 10th Jul 1992 |
| 192.195.200.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.201.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.202.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.205.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.206.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.207.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.211.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.213.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.217.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.218.0/24 | 256 | ARIN | US | 5th Aug 1992 |
| 192.195.22.0/24 | 256 | ARIN | US | 10th Jul 1992 |