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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 159.164.0.0/16 | 65.5k | ARIN |  US | 6th May 1992 |
| 159.165.0.0/16 | 65.5k | ARIN | US | 6th May 1992 |
| 159.167.0.0/16 | 65.5k | RIPE NCC |  GB | 1st Sept 1993 |
| 159.17.0.0/16 | 65.5k | ARIN | US | 26th Feb 1992 |
| 159.170.0.0/16 | 65.5k | RIPE NCC | GB | 1st Jan 1984 |
| 159.173.0.0/16 | 65.5k | RIPE NCC |  FR | 12th May 1992 |
| 159.176.0.0/16 | 65.5k | ARIN | US | 12th May 1992 |
| 159.177.0.0/16 | 65.5k | ARIN |  CA | 12th May 1992 |
| 159.180.64.0/19 | 8.2k | RIPE NCC | GB | 1st Sept 1993 |
| 159.184.0.0/14 | 262k | ARIN | US | 19th May 1992 |
| 159.188.0.0/16 | 65.5k | ARIN | US | 19th May 1992 |
| 159.194.0.0/17 | 32.8k | RIPE NCC |  SC | 26th May 1992 |
| 159.194.192.0/24 | 256 | RIPE NCC | SC | 26th May 1992 |
| 159.194.193.0/24 | 256 | RIPE NCC | CA | 26th May 1992 |
| 159.198.0.0/20 | 4.1k | ARIN | US | 28th May 1992 |
| 159.198.48.0/20 | 4.1k | ARIN | US | 28th May 1992 |
| 159.198.80.0/20 | 4.1k | ARIN | US | 28th May 1992 |
| 159.198.96.0/19 | 8.2k | ARIN | US | 28th May 1992 |
| 159.199.0.0/16 | 65.5k | ARIN | US | 4th Jun 1992 |
| 159.20.32.0/19 | 8.2k | RIPE NCC | GB | 2nd Sept 2011 |
| 159.200.0.0/17 | 32.8k | RIPE NCC |  HK | 1st Sept 1993 |
| 159.200.128.0/18 | 16.4k | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.192.0/21 | 2k | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.200.0/24 | 256 | RIPE NCC |  RU | 1st Sept 1993 |
| 159.200.201.0/24 | 256 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.202.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.204.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.206.0/23 | 512 | RIPE NCC |  AT | 1st Sept 1993 |
| 159.200.208.0/20 | 4.1k | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.224.0/22 | 1k | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.228.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.230.0/23 | 512 | RIPE NCC |  DE | 1st Sept 1993 |
| 159.200.232.0/24 | 256 | RIPE NCC |  UA | 1st Sept 1993 |
| 159.200.233.0/24 | 256 | RIPE NCC | UA | 1st Sept 1993 |
| 159.200.234.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.236.0/24 | 256 | RIPE NCC | UA | 1st Sept 1993 |
| 159.200.237.0/24 | 256 | RIPE NCC | UA | 1st Sept 1993 |
| 159.200.238.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.244.0/23 | 512 | RIPE NCC | HK | 1st Sept 1993 |
| 159.200.246.0/23 | 512 | RIPE NCC | UA | 1st Sept 1993 |
| 159.200.248.0/21 | 2k | RIPE NCC | HK | 1st Sept 1993 |
| 159.202.0.0/16 | 65.5k | ARIN | US | 4th Jun 1992 |
| 159.205.0.0/16 | 65.5k | RIPE NCC |  PL | 20th Sept 2011 |
| 159.210.0.0/16 | 65.5k | RIPE NCC |  IT | 1st Sept 1993 |
| 159.214.128.0/18 | 16.4k | ARIN | US | 6th May 1992 |
| 159.219.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 159.222.96.0/19 | 8.2k | ARIN | US | 10th Jun 1992 |
| 159.228.0.0/16 | 65.5k | APNIC |  JP | 8th Feb 2011 |
| 159.235.0.0/16 | 65.5k | ARIN | US | 27th Jul 2018 |
| 159.236.0.0/16 | 65.5k | ARIN | US | 24th Jul 2023 |