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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 147.185.35.0/24 | 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 |
| 147.189.0.0/20 | 4.1k | RIPE NCC |  GB | 8th Jul 1991 |
| 147.189.154.0/24 | 256 | RIPE NCC | GB | 8th Jul 1991 |
| 147.189.160.0/24 | 256 | RIPE NCC | GB | 8th Jul 1991 |
| 147.189.192.0/20 | 4.1k | RIPE NCC |  MT | 8th Jul 1991 |
| 147.189.215.0/24 | 256 | RIPE NCC | GB | 8th Jul 1991 |
| 147.189.240.0/20 | 4.1k | RIPE NCC | GB | 8th Jul 1991 |
| 147.189.96.0/19 | 8.2k | RIPE NCC |  DE | 8th Jul 1991 |
| 147.193.0.0/16 | 65.5k | RIPE NCC | GB | 9th 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 |
| 147.201.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 147.204.0.0/16 | 65.5k | RIPE NCC | DE | 11th Apr 1991 |
| 147.208.0.0/16 | 65.5k | ARIN | US | 19th Jul 1991 |
| 147.212.0.0/16 | 65.5k | APNIC |  AU | 14th Feb 2011 |
| 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 |
| 147.234.106.0/23 | 512 | RIPE NCC |  IL | 1st Jan 1984 |
| 147.234.108.0/22 | 1k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.112.0/20 | 4.1k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.160.0/24 | 256 | ARIN | US | 20th Jan 2026 |
| 147.234.161.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.162.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.164.0/22 | 1k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.168.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.172.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.176.0/21 | 2k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.185.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.186.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.188.0/22 | 1k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.2.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.34.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.40.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.56.0/21 | 2k | RIPE NCC | IL | 1st Jan 1984 |
| 147.234.91.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.236.102.0/23 | 512 | RIPE NCC | IL | 1st Jan 1984 |
| 147.236.162.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.236.167.0/24 | 256 | RIPE NCC | IL | 1st Jan 1984 |
| 147.236.196.0/22 | 1k | RIPE NCC | IL | 1st Jan 1984 |