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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 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 |
| 45.84.89.0/24 | 256 | RIPE NCC | GB | 31st May 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 |
| 45.9.23.0/24 | 256 | RIPE NCC | GB | 3rd May 2021 |
| 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 |
| 46.19.240.0/21 | 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 |
| 46.29.88.0/21 | 2k | RIPE NCC | GB | 9th Aug 2010 |
| 46.33.21.0/24 | 256 | RIPE NCC | GB | 20th Aug 2010 |
| 46.36.192.0/21 | 2k | RIPE NCC | GB | 2nd Nov 2010 |
| 46.43.128.0/18 | 16.4k | RIPE NCC | GB | 17th Aug 2010 |
| 5.100.168.0/21 | 2k | RIPE NCC | GB | 26th Jun 2012 |
| 5.133.80.0/22 | 1k | RIPE NCC | GB | 9th Nov 2018 |
| 5.144.152.0/24 | 256 | RIPE NCC | GB | 12th Jul 2012 |
| 5.144.153.0/24 | 256 | RIPE NCC | GB | 12th Jul 2012 |
| 5.144.154.0/23 | 512 | RIPE NCC | GB | 12th Jul 2012 |
| 5.154.232.0/24 | 256 | RIPE NCC | GB | 19th Jul 2012 |
| 5.182.76.0/22 | 1k | RIPE NCC | GB | 5th Apr 2019 |
| 5.183.112.0/22 | 1k | RIPE NCC | GB | 10th Apr 2019 |
| 5.252.208.0/22 | 1k | RIPE NCC | GB | 6th Feb 2019 |
| 5.253.108.0/22 | 1k | RIPE NCC | GB | 8th Feb 2019 |
| 5.255.60.0/24 | 256 | RIPE NCC | GB | 14th Sept 2012 |
| 5.45.48.0/21 | 2k | RIPE NCC | GB | 25th May 2012 |
| 5.63.18.0/24 | 256 | RIPE NCC | GB | 15th Jan 2024 |
| 51.130.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.147.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.2.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.234.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.238.0.0/15 | 131k | RIPE NCC | GB | 1st Sept 1993 |
| 51.242.0.0/15 | 131k | RIPE NCC | GB | 1st Sept 1993 |
| 51.246.0.0/15 | 131k | RIPE NCC | GB | 1st Sept 1993 |
| 51.251.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.33.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |