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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,968 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 147.141.0.0/16 | 65.5k | ARIN |  US | 22nd Mar 1991 |
| 147.16.0.0/14 | 262k | ARIN | US | 17th Apr 1991 |
| 147.160.148.0/24 | 256 | ARIN |  CA | 9th Sept 2019 |
| 147.160.150.0/23 | 512 | ARIN | US | 30th May 2019 |
| 147.160.152.0/23 | 512 | ARIN | US | 17th May 2019 |
| 147.160.16.0/21 | 2k | ARIN | US | 15th Aug 2019 |
| 147.160.52.0/23 | 512 | ARIN | US | 5th Aug 2019 |
| 147.160.55.0/24 | 256 | ARIN | US | 30th May 2019 |
| 147.160.64.0/18 | 16.4k | APNIC |  IN | 29th Apr 1991 |
| 147.160.7.0/24 | 256 | ARIN | US | 24th Jul 2019 |
| 147.161.20.0/24 | 256 | RIPE NCC |  DE | 1st May 1991 |
| 147.161.8.0/21 | 2k | RIPE NCC |  IL | 1st May 1991 |
| 147.167.0.0/16 | 65.5k | RIPE NCC |  CH | 9th May 1991 |
| 147.170.0.0/16 | 65.5k | ARIN | US | 20th Jun 1991 |
| 147.179.0.0/16 | 65.5k | ARIN | US | 5th Jul 1991 |
| 147.184.0.0/16 | 65.5k | RIPE NCC |  GB | 5th Jul 1991 |
| 147.185.0.0/20 | 4.1k | ARIN | US | 5th Jul 1991 |
| 147.185.108.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.128.0/23 | 512 | ARIN | US | 5th Jul 1991 |
| 147.185.140.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.168.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 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 |
| 147.185.191.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.194.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 147.185.195.0/24 | 256 | RIPE NCC | GB | 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 |
| 147.185.28.0/22 | 1k | ARIN | US | 5th Jul 1991 |
| 147.185.32.0/23 | 512 | ARIN | US | 5th Jul 1991 |