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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 206.53.138.0/24 | 256 | ARIN |  GB | 11th Feb 2015 |
| 207.207.206.0/24 | 256 | RIPE NCC | GB | 14th Oct 1996 |
| 207.207.222.0/24 | 256 | RIPE NCC | GB | 14th Oct 1996 |
| 207.229.64.0/24 | 256 | RIPE NCC | GB | 30th Dec 1996 |
| 209.100.0.0/16 | 65.5k | RIPE NCC | GB | 13th Jun 1997 |
| 209.42.3.0/24 | 256 | RIPE NCC | GB | 14th Mar 1997 |
| 212.104.157.0/24 | 256 | RIPE NCC | GB | 29th Dec 1998 |
| 212.108.80.0/23 | 512 | RIPE NCC | GB | 15th Jan 1999 |
| 212.108.84.0/24 | 256 | RIPE NCC | GB | 15th Jan 1999 |
| 212.117.224.0/19 | 8.2k | RIPE NCC | GB | 9th Jun 2000 |
| 212.119.56.0/22 | 1k | RIPE NCC | GB | 6th Nov 2018 |
| 212.132.0.0/19 | 8.2k | RIPE NCC | GB | 19th Nov 1998 |
| 212.173.0.0/17 | 32.8k | RIPE NCC | GB | 12th May 1999 |
| 212.21.104.0/21 | 2k | RIPE NCC | GB | 7th Sept 1999 |
| 212.21.112.0/21 | 2k | RIPE NCC | GB | 7th Sept 1999 |
| 212.21.120.0/22 | 1k | RIPE NCC | GB | 7th Sept 1999 |
| 212.21.124.0/23 | 512 | RIPE NCC | GB | 7th Sept 1999 |
| 212.21.127.0/24 | 256 | RIPE NCC | GB | 7th Sept 1999 |
| 212.225.0.0/19 | 8.2k | RIPE NCC | GB | 24th Aug 1998 |
| 212.225.32.0/19 | 8.2k | RIPE NCC | GB | 7th Apr 1999 |
| 212.225.64.0/18 | 16.4k | RIPE NCC | GB | 7th Apr 1999 |
| 212.23.193.0/24 | 256 | RIPE NCC | GB | 4th Nov 2021 |
| 212.237.212.0/22 | 1k | RIPE NCC | GB | 25th Sept 1998 |
| 212.248.128.0/17 | 32.8k | RIPE NCC | GB | 4th Dec 2000 |
| 212.32.28.0/24 | 256 | RIPE NCC | GB | 3rd Feb 1998 |
| 212.32.44.0/24 | 256 | RIPE NCC | GB | 3rd Feb 1998 |
| 212.43.160.0/19 | 8.2k | RIPE NCC | GB | 15th Apr 1999 |
| 212.46.134.0/23 | 512 | RIPE NCC | GB | 12th May 1998 |
| 212.46.136.0/23 | 512 | RIPE NCC | GB | 12th May 1998 |
| 212.46.146.0/23 | 512 | RIPE NCC | GB | 12th May 1998 |
| 212.46.150.0/23 | 512 | RIPE NCC | GB | 12th May 1998 |
| 212.46.152.0/22 | 1k | RIPE NCC | GB | 12th May 1998 |
| 212.46.156.0/23 | 512 | RIPE NCC | GB | 12th May 1998 |
| 212.47.34.0/24 | 256 | RIPE NCC | GB | 20th Jan 2026 |
| 212.47.52.0/24 | 256 | RIPE NCC | GB | 16th Mar 2026 |
| 212.52.6.0/24 | 256 | RIPE NCC | GB | 5th Nov 2021 |
| 212.97.72.0/21 | 2k | RIPE NCC | GB | 5th Feb 1999 |
| 213.109.180.0/22 | 1k | RIPE NCC | GB | 6th Nov 2018 |
| 213.12.0.0/16 | 65.5k | RIPE NCC | GB | 24th Aug 1999 |
| 213.147.224.0/19 | 8.2k | RIPE NCC | GB | 20th Jan 2003 |
| 213.170.200.0/22 | 1k | RIPE NCC | GB | 6th Nov 2018 |
| 213.177.32.0/19 | 8.2k | RIPE NCC | GB | 12th Jan 2001 |
| 213.178.144.0/22 | 1k | RIPE NCC | GB | 18th Mar 2019 |
| 213.187.32.0/19 | 8.2k | RIPE NCC | GB | 5th Feb 2001 |
| 213.221.160.0/19 | 8.2k | RIPE NCC | GB | 4th Oct 2000 |
| 213.225.128.0/19 | 8.2k | RIPE NCC | GB | 24th May 2000 |
| 213.234.32.0/19 | 8.2k | RIPE NCC | GB | 5th Dec 2001 |
| 213.237.192.0/18 | 16.4k | RIPE NCC | GB | 18th Mar 2003 |
| 213.254.166.0/23 | 512 | RIPE NCC | GB | 17th Oct 2000 |
| 216.116.131.0/24 | 256 | RIPE NCC | GB | 1st Jun 2018 |