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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United Kingdom
2,663 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 158.124.0.0/16 | 65.5k | RIPE NCC |  GB | 2nd Mar 1992 |
| 158.152.0.0/16 | 65.5k | RIPE NCC | GB | 13th Mar 1992 |
| 158.178.254.0/23 | 512 | RIPE NCC | GB | 24th Mar 1992 |
| 158.179.0.0/24 | 256 | RIPE NCC | GB | 24th Mar 1992 |
| 158.180.224.0/23 | 512 | RIPE NCC | GB | 24th Mar 1992 |
| 158.180.96.0/19 | 8.2k | RIPE NCC | GB | 24th Mar 1992 |
| 158.218.0.0/16 | 65.5k | RIPE NCC | GB | 1st Apr 1992 |
| 159.100.176.0/20 | 4.1k | RIPE NCC | GB | 31st Mar 1992 |
| 159.114.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 159.167.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 159.170.0.0/16 | 65.5k | RIPE NCC | GB | 1st Jan 1984 |
| 159.180.64.0/19 | 8.2k | RIPE NCC | GB | 1st Sept 1993 |
| 159.20.32.0/19 | 8.2k | RIPE NCC | GB | 2nd Sept 2011 |
| 159.219.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 159.30.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 160.104.0.0/16 | 65.5k | RIPE NCC | GB | 5th Apr 2004 |
| 160.38.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 163.169.0.0/16 | 65.5k | RIPE NCC | GB | 8th Sept 1992 |
| 164.153.24.0/22 | 1k | RIPE NCC | GB | 14th Feb 2019 |
| 164.37.41.0/24 | 256 | RIPE NCC | GB | 31st Jan 1993 |
| 164.6.0.0/16 | 65.5k | RIPE NCC | GB | 25th Sept 1992 |
| 164.93.128.0/17 | 32.8k | RIPE NCC | GB | 12th Nov 2013 |
| 165.65.196.0/22 | 1k | RIPE NCC | GB | 12th Apr 1993 |
| 165.65.200.0/22 | 1k | RIPE NCC | GB | 12th Apr 1993 |
| 165.84.224.0/21 | 2k | RIPE NCC | GB | 16th Feb 2016 |
| 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 |
| 176.10.94.0/24 | 256 | RIPE NCC | GB | 29th Jan 2025 |
| 176.113.45.0/24 | 256 | RIPE NCC | GB | 3rd Jul 2020 |
| 176.122.192.0/23 | 512 | RIPE NCC | GB | 26th Jul 2012 |
| 176.124.249.0/24 | 256 | RIPE NCC | GB | 24th Jul 2023 |
| 176.126.116.0/24 | 256 | RIPE NCC | GB | 26th Oct 2021 |
| 176.126.117.0/24 | 256 | RIPE NCC | GB | 26th Oct 2021 |
| 176.24.0.0/14 | 262k | RIPE NCC | GB | 19th May 2011 |
| 178.107.48.0/20 | 4.1k | RIPE NCC | GB | 18th Nov 2009 |
| 178.107.64.0/18 | 16.4k | RIPE NCC | GB | 18th Nov 2009 |
| 178.18.112.0/22 | 1k | RIPE NCC | GB | 13th Apr 2010 |
| 178.18.118.0/24 | 256 | RIPE NCC | GB | 13th Apr 2010 |
| 178.215.128.0/20 | 4.1k | RIPE NCC | GB | 15th Jul 2010 |
| 178.216.244.0/24 | 256 | RIPE NCC | GB | 8th Jul 2020 |
| 178.249.40.0/21 | 2k | RIPE NCC | GB | 19th May 2010 |
| 178.250.72.0/21 | 2k | RIPE NCC | GB | 2nd Jun 2010 |
| 185.0.32.0/24 | 256 | RIPE NCC | GB | 12th Jun 2023 |
| 185.1.101.0/24 | 256 | RIPE NCC | GB | 2nd Nov 2017 |
| 185.1.104.0/24 | 256 | RIPE NCC | GB | 17th Nov 2017 |
| 185.1.136.0/24 | 256 | RIPE NCC | GB | 11th Mar 2020 |
| 185.1.141.0/24 | 256 | RIPE NCC | GB | 26th Aug 2019 |
| 185.1.195.0/24 | 256 | RIPE NCC | GB | 27th Nov 2020 |
| 185.1.207.0/24 | 256 | RIPE NCC | GB | 7th Jun 2021 |
| 185.1.232.0/24 | 256 | RIPE NCC | GB | 8th Feb 2022 |