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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,431 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 147.185.173.0/24 | 256 | ARIN |  US | 5th Jul 1991 |
| 147.185.174.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.179.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.18.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.180.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.190.0/24 | 256 | ARIN | US | 27th Oct 2021 |
| 147.185.191.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.194.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.198.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.20.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.204.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.209.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.211.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.212.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.214.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.218.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.220.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.227.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.228.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.234.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.236.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.24.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.240.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.244.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.248.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.252.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.26.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.32.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.35.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.36.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.44.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.48.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.52.0/22 | 1k | ARIN | US | 16th Jun 2026 |
| 147.185.56.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.64.0/21 | 2k | ARIN | US | 5th Jul 1991 |
| 147.185.76.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.80.0/21 | 2k | ARIN | US | 5th Jul 1991 |
| 147.185.92.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.96.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.195.0.0/16 | 65.5k | ARIN | US | 10th Jul 1991 |
| 147.20.0.0/16 | 65.5k | ARIN | US | 22nd Apr 1991 |
| 147.208.0.0/16 | 65.5k | ARIN | US | 19th Jul 1991 |
| 147.22.0.0/16 | 65.5k | ARIN | US | 22nd Apr 1991 |
| 147.223.0.0/16 | 65.5k | ARIN | US | 28th Mar 1991 |
| 147.234.160.0/24 | 256 | ARIN | US | 20th Jan 2026 |
| 147.3.0.0/16 | 65.5k | ARIN | US | 12th Mar 1991 |
| 147.61.0.0/16 | 65.5k | ARIN | US | 5th Jul 1991 |
| 148.117.0.0/16 | 65.5k | ARIN |  CA | 2nd Apr 1991 |
| 148.127.0.0/16 | 65.5k | ARIN | US | 9th Apr 1991 |
| 148.130.0.0/16 | 65.5k | ARIN | US | 9th Apr 1991 |