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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
85,041 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 170.226.58.0/23 | 512 | ARIN |  US | 21st Apr 1995 |
| 170.226.60.0/22 | 1k | ARIN | US | 21st Apr 1995 |
| 170.226.64.0/18 | 16.4k | ARIN | US | 21st Apr 1995 |
| 170.227.0.0/16 | 65.5k | ARIN | US | 21st Apr 1995 |
| 170.231.136.0/22 | 1k | LACNIC |  AR | 21st Jun 2016 |
| 170.231.68.0/22 | 1k | LACNIC | AR | 17th Jun 2016 |
| 170.234.0.0/16 | 65.5k | ARIN | US | 13th May 1994 |
| 170.236.0.0/16 | 65.5k | RIPE NCC |  CH | 26th Mar 1997 |
| 170.237.128.0/17 | 32.8k | RIPE NCC | CH | 26th Mar 1997 |
| 170.237.16.0/20 | 4.1k | RIPE NCC | CH | 26th Mar 1997 |
| 170.237.32.0/19 | 8.2k | RIPE NCC | CH | 26th Mar 1997 |
| 170.237.64.0/18 | 16.4k | RIPE NCC | CH | 26th Mar 1997 |
| 170.238.220.0/22 | 1k | LACNIC |  MX | 11th Nov 2016 |
| 170.238.225.0/24 | 256 | LACNIC |  BR | 6th Dec 2016 |
| 170.238.67.0/24 | 256 | LACNIC | AR | 28th Nov 2016 |
| 170.240.0.0/14 | 262k | ARIN | US | 3rd Mar 1998 |
| 170.245.140.0/22 | 1k | LACNIC | BR | 20th Jan 2017 |
| 170.246.48.0/22 | 1k | LACNIC | AR | 27th Jan 2017 |
| 170.246.64.0/22 | 1k | RIPE NCC |  NL | 10th Feb 2017 |
| 170.247.232.0/22 | 1k | LACNIC | BR | 17th Feb 2017 |
| 170.248.12.0/23 | 512 | APNIC |  IN | 24th Jan 1994 |
| 170.248.138.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.248.14.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.248.184.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.248.190.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.248.2.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.248.46.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.249.92.0/22 | 1k | ARIN | US | 6th Mar 2019 |
| 170.251.12.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.140.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.142.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.251.150.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.251.156.0/23 | 512 | APNIC | IN | 24th Jan 1994 |
| 170.251.158.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.16.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.168.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.56.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.62.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.36.0.0/16 | 65.5k | ARIN | US | 3rd Feb 1994 |
| 170.37.200.0/23 | 512 | ARIN | US | 3rd Feb 1994 |
| 170.37.202.0/24 | 256 | ARIN | US | 3rd Feb 1994 |
| 170.37.203.0/24 | 256 | RIPE NCC |  FR | 3rd Feb 1994 |
| 170.37.204.0/23 | 512 | RIPE NCC | FR | 3rd Feb 1994 |
| 170.37.206.0/24 | 256 | RIPE NCC | FR | 3rd Feb 1994 |
| 170.37.207.0/24 | 256 | ARIN | US | 3rd Feb 1994 |
| 170.37.208.0/20 | 4.1k | ARIN | US | 3rd Feb 1994 |
| 170.39.0.0/22 | 1k | ARIN | US | 31st Jul 2020 |
| 170.39.100.0/24 | 256 | ARIN |  CA | 3rd Oct 2024 |
| 170.39.137.0/24 | 256 | ARIN | US | 8th Jul 2020 |
| 170.39.188.0/24 | 256 | ARIN | US | 8th Sept 2020 |