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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through RIPE NCC, largest first.
Unannounced blocks in United Kingdom
2,577 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 31.99.154.0/23 | 512 | RIPE NCC |  GB | 25th Nov 2010 |
| 31.99.156.0/22 | 1k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.216.0/21 | 2k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.224.0/19 | 8.2k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.64.0/18 | 16.4k | RIPE NCC | GB | 25th Nov 2010 |
| 36.255.148.0/22 | 1k | RIPE NCC | GB | 19th Feb 2016 |
| 37.122.192.0/21 | 2k | RIPE NCC | GB | 14th Feb 2012 |
| 37.75.232.0/21 | 2k | RIPE NCC | GB | 31st Jan 2012 |
| 40.17.0.0/16 | 65.5k | RIPE NCC | GB | 23rd Apr 1991 |
| 40.21.0.0/16 | 65.5k | RIPE NCC | GB | 23rd Apr 1991 |
| 40.25.0.0/16 | 65.5k | RIPE NCC | GB | 23rd Apr 1991 |
| 45.12.188.0/22 | 1k | RIPE NCC | GB | 2nd May 2019 |
| 45.132.228.0/22 | 1k | RIPE NCC | GB | 24th Jul 2019 |
| 45.133.240.0/24 | 256 | RIPE NCC | GB | 20th Mar 2023 |
| 45.137.36.0/22 | 1k | RIPE NCC | GB | 5th Aug 2019 |
| 45.139.80.0/22 | 1k | RIPE NCC | GB | 8th Aug 2019 |
| 45.14.168.0/22 | 1k | RIPE NCC | GB | 9th May 2019 |
| 45.142.12.0/24 | 256 | RIPE NCC | GB | 4th Jun 2021 |
| 45.144.144.0/22 | 1k | RIPE NCC | GB | 22nd Aug 2019 |
| 45.145.32.0/22 | 1k | RIPE NCC | GB | 23rd Aug 2019 |
| 45.146.144.0/22 | 1k | RIPE NCC | GB | 28th Aug 2019 |
| 45.146.176.0/22 | 1k | RIPE NCC | GB | 28th Aug 2019 |
| 45.146.72.0/22 | 1k | RIPE NCC | GB | 28th Aug 2019 |
| 45.147.88.0/22 | 1k | RIPE NCC | GB | 30th Aug 2019 |
| 45.154.40.0/22 | 1k | RIPE NCC | GB | 16th Sept 2019 |
| 45.155.180.0/22 | 1k | RIPE NCC | GB | 19th Sept 2019 |
| 45.155.188.0/22 | 1k | RIPE NCC | GB | 19th Sept 2019 |
| 45.155.232.0/22 | 1k | RIPE NCC | GB | 19th Sept 2019 |
| 45.156.80.0/22 | 1k | RIPE NCC | GB | 20th Sept 2019 |
| 45.157.252.0/22 | 1k | RIPE NCC | GB | 26th Sept 2019 |
| 45.86.120.0/22 | 1k | RIPE NCC | GB | 12th Jun 2019 |
| 45.88.164.0/22 | 1k | RIPE NCC | GB | 19th Jun 2019 |
| 45.92.220.0/22 | 1k | RIPE NCC | GB | 2nd Jul 2019 |
| 46.102.177.0/24 | 256 | RIPE NCC | GB | 25th Jun 2010 |
| 46.16.0.0/21 | 2k | RIPE NCC | GB | 27th Sept 2010 |
| 46.183.22.0/24 | 256 | RIPE NCC | GB | 22nd Jan 2026 |
| 46.19.240.0/21 | 2k | RIPE NCC | GB | 18th Nov 2010 |
| 46.226.248.0/21 | 2k | RIPE NCC | GB | 26th Jan 2011 |
| 46.226.48.0/21 | 2k | RIPE NCC | GB | 20th Jan 2011 |
| 46.235.5.0/24 | 256 | RIPE NCC | GB | 8th Feb 2011 |
| 46.237.128.0/18 | 16.4k | RIPE NCC | GB | 26th Jan 2011 |
| 46.247.44.0/22 | 1k | RIPE NCC | GB | 1st Feb 2011 |
| 46.247.48.0/21 | 2k | RIPE NCC | GB | 1st Feb 2011 |
| 46.247.56.0/23 | 512 | RIPE NCC | GB | 1st Feb 2011 |
| 46.247.62.0/23 | 512 | RIPE NCC | GB | 1st Feb 2011 |
| 46.255.0.0/21 | 2k | RIPE NCC | GB | 23rd Dec 2010 |
| 46.28.48.0/21 | 2k | RIPE NCC | GB | 20th Jul 2010 |
| 46.29.36.0/24 | 256 | RIPE NCC | GB | 16th Jan 2025 |
| 46.29.88.0/21 | 2k | RIPE NCC | GB | 9th Aug 2010 |
| 46.36.192.0/21 | 2k | RIPE NCC | GB | 2nd Nov 2010 |