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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,430 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 147.23.0.0/16 | 65.5k | ARIN | US | 22nd Apr 1991 |
| 147.234.160.0/24 | 256 | ARIN | US | 20th Jan 2026 |
| 147.24.0.0/15 | 131k | ARIN | US | 22nd Apr 1991 |
| 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 |
| 148.131.0.0/16 | 65.5k | ARIN | US | 11th Apr 1991 |
| 148.132.0.0/16 | 65.5k | ARIN | US | 11th Apr 1991 |
| 148.133.0.0/16 | 65.5k | ARIN | US | 11th Apr 1991 |
| 148.146.0.0/16 | 65.5k | ARIN | US | 18th Apr 1991 |
| 148.152.0.0/16 | 65.5k | ARIN | US | 24th Apr 1991 |
| 148.155.0.0/16 | 65.5k | ARIN | US | 30th Apr 1991 |
| 148.157.0.0/16 | 65.5k | ARIN | US | 30th Apr 1991 |
| 148.158.0.0/16 | 65.5k | ARIN | US | 30th Apr 1991 |
| 148.16.0.0/12 | 1M | ARIN | US | 13th Mar 1991 |
| 148.163.188.0/22 | 1k | ARIN | US | 5th Jun 2018 |
| 148.171.0.0/16 | 65.5k | ARIN | US | 9th May 1991 |
| 148.172.0.0/16 | 65.5k | ARIN | US | 9th May 1991 |
| 148.174.0.0/16 | 65.5k | ARIN | US | 13th May 1991 |
| 148.175.0.0/16 | 65.5k | ARIN | US | 1st Dec 1995 |
| 148.180.0.0/16 | 65.5k | ARIN | US | 15th Apr 1991 |
| 148.183.0.0/16 | 65.5k | ARIN | US | 16th May 1991 |
| 148.189.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.190.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.191.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.192.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.193.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.194.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.222.158.0/24 | 256 | ARIN | US | 24th Apr 2025 |
| 148.224.48.0/22 | 1k | ARIN | US | 22nd May 2025 |
| 148.50.0.0/16 | 65.5k | ARIN | US | 13th Mar 1991 |