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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,075 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 170.67.0.0/16 | 65.5k | ARIN |  US | 25th Feb 1994 |
| 170.71.0.0/16 | 65.5k | ARIN | US | 6th Feb 2012 |
| 170.73.0.0/16 | 65.5k | ARIN | US | 3rd Mar 1994 |
| 170.76.0.0/17 | 32.8k | ARIN | US | 20th Dec 2018 |
| 170.76.130.0/24 | 256 | ARIN | US | 7th Nov 2016 |
| 170.76.134.0/24 | 256 | ARIN | US | 17th Apr 2017 |
| 170.76.210.0/24 | 256 | ARIN | US | 13th Dec 2017 |
| 170.76.220.0/23 | 512 | ARIN | US | 17th Jan 2018 |
| 170.76.228.0/23 | 512 | ARIN | US | 27th Mar 2018 |
| 170.76.231.0/24 | 256 | ARIN | US | 22nd May 2018 |
| 170.76.240.0/24 | 256 | ARIN | US | 20th Apr 2020 |
| 170.79.212.0/22 | 1k | LACNIC |  BR | 17th Oct 2016 |
| 170.80.248.0/22 | 1k | LACNIC |  HT | 8th Dec 2016 |
| 170.81.124.0/22 | 1k | ARIN | US | 11th Jan 2022 |
| 170.83.192.0/22 | 1k | LACNIC | HT | 17th Jan 2017 |
| 170.84.188.0/22 | 1k | LACNIC |  MX | 7th Jun 2016 |
| 170.84.254.0/24 | 256 | LACNIC |  AW | 10th Aug 2022 |
| 170.84.32.0/22 | 1k | LACNIC | BR | 20th May 2016 |
| 170.87.0.0/16 | 65.5k | ARIN | US | 17th Mar 1994 |
| 170.90.0.0/22 | 1k | ARIN | US | 18th Mar 1994 |
| 170.90.128.0/17 | 32.8k | ARIN | US | 1st Sept 2017 |
| 170.90.16.0/20 | 4.1k | ARIN | US | 1st Sept 2017 |
| 170.90.32.0/19 | 8.2k | ARIN | US | 1st Sept 2017 |
| 170.90.4.0/22 | 1k | ARIN | US | 1st Sept 2017 |
| 170.90.64.0/18 | 16.4k | ARIN | US | 1st Sept 2017 |
| 170.90.8.0/21 | 2k | ARIN | US | 1st Sept 2017 |
| 171.200.0.0/14 | 262k | ARIN | US | 1st Feb 1995 |
| 171.204.0.0/15 | 131k | ARIN | US | 1st Feb 1995 |
| 171.206.0.0/16 | 65.5k | ARIN | US | 1st Feb 1995 |
| 171.22.124.0/22 | 1k | RIPE NCC |  CY | 31st Jan 2019 |
| 171.22.19.0/24 | 256 | RIPE NCC |  BG | 30th Jan 2019 |
| 171.22.200.0/22 | 1k | RIPE NCC | US | 1st Feb 2019 |
| 171.22.236.0/22 | 1k | RIPE NCC |  RU | 1st Feb 2019 |
| 171.22.242.0/24 | 256 | RIPE NCC | RU | 10th Jan 2024 |
| 171.22.243.0/24 | 256 | RIPE NCC |  VG | 10th Jan 2024 |
| 171.22.36.0/22 | 1k | RIPE NCC |  BZ | 30th Jan 2019 |
| 171.25.0.0/17 | 32.8k | RIPE NCC |  CH | 9th Aug 1994 |
| 171.25.176.0/24 | 256 | RIPE NCC |  CZ | 12th Jan 2012 |
| 171.25.178.0/24 | 256 | RIPE NCC |  DE | 11th Apr 2012 |
| 171.25.179.0/24 | 256 | RIPE NCC |  NL | 12th Jan 2012 |
| 171.25.184.0/22 | 1k | RIPE NCC | RU | 13th Jan 2012 |
| 171.25.191.0/24 | 256 | RIPE NCC |  IT | 13th Jan 2012 |
| 171.25.212.0/22 | 1k | RIPE NCC | RU | 17th Jan 2012 |
| 171.25.244.0/22 | 1k | RIPE NCC | RU | 20th Jan 2012 |
| 171.25.252.0/22 | 1k | RIPE NCC | RU | 20th Jan 2012 |
| 171.28.0.0/15 | 131k | RIPE NCC |  GB | 9th Jan 1995 |
| 171.30.0.0/16 | 65.5k | RIPE NCC | GB | 9th Jan 1995 |
| 171.33.0.0/18 | 16.4k | RIPE NCC | CH | 10th Feb 1995 |
| 171.33.136.0/21 | 2k | RIPE NCC | CZ | 3rd Jul 2012 |
| 171.33.224.0/21 | 2k | RIPE NCC | NL | 3rd Jul 2012 |