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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,584 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 5.183.163.0/24 | 256 | RIPE NCC |  SM | 14th Jan 2025 |
| 5.183.236.0/22 | 1k | RIPE NCC |  BE | 11th Apr 2019 |
| 5.183.244.0/22 | 1k | RIPE NCC |  AT | 11th Apr 2019 |
| 5.187.34.0/24 | 256 | RIPE NCC |  CZ | 9th Aug 2012 |
| 5.187.36.0/23 | 512 | RIPE NCC |  CH | 9th Aug 2012 |
| 5.198.128.0/22 | 1k | RIPE NCC | CZ | 24th Aug 2012 |
| 5.198.132.0/22 | 1k | RIPE NCC | CZ | 24th Aug 2012 |
| 5.207.0.0/16 | 65.5k | RIPE NCC |  UA | 5th Sept 2012 |
| 5.220.0.0/15 | 131k | RIPE NCC |  IR | 4th Sept 2012 |
| 5.222.0.0/17 | 32.8k | RIPE NCC |  DE | 4th Sept 2012 |
| 5.222.128.0/17 | 32.8k | RIPE NCC | DE | 4th Sept 2012 |
| 5.252.136.0/22 | 1k | RIPE NCC | CH | 5th Feb 2019 |
| 5.252.140.0/22 | 1k | RIPE NCC | DE | 5th Feb 2019 |
| 5.252.248.0/22 | 1k | RIPE NCC | DE | 7th Feb 2019 |
| 5.253.108.0/22 | 1k | RIPE NCC |  GB | 8th Feb 2019 |
| 5.253.116.0/22 | 1k | RIPE NCC |  RO | 8th Feb 2019 |
| 5.253.160.0/22 | 1k | RIPE NCC | RO | 8th Feb 2019 |
| 5.253.225.0/24 | 256 | RIPE NCC | IR | 24th Jan 2022 |
| 5.253.226.0/24 | 256 | RIPE NCC |  NL | 24th Jan 2022 |
| 5.253.231.0/24 | 256 | RIPE NCC | BE | 11th Feb 2019 |
| 5.253.96.0/22 | 1k | RIPE NCC | IR | 8th Feb 2019 |
| 5.255.152.0/21 | 2k | RIPE NCC | NL | 14th Sept 2012 |
| 5.255.62.0/23 | 512 | RIPE NCC |  GE | 14th Sept 2012 |
| 5.28.192.0/18 | 16.4k | RIPE NCC | DE | 8th May 2012 |
| 5.34.168.0/21 | 2k | RIPE NCC |  SK | 11th May 2012 |
| 5.42.216.0/24 | 256 | RIPE NCC |  HK | 7th Apr 2022 |
| 5.44.144.0/20 | 4.1k | RIPE NCC |  TR | 23rd May 2012 |
| 5.45.48.0/21 | 2k | RIPE NCC | GB | 25th May 2012 |
| 5.57.128.0/18 | 16.4k | RIPE NCC |  PL | 1st Jun 2012 |
| 5.57.214.0/24 | 256 | RIPE NCC | PL | 30th Jul 2021 |
| 5.61.212.0/22 | 1k | RIPE NCC |  FR | 8th Jun 2012 |
| 5.61.93.0/24 | 256 | RIPE NCC |  FI | 8th Jun 2012 |
| 5.61.95.0/24 | 256 | RIPE NCC | FI | 8th Jun 2012 |
| 5.63.144.0/21 | 2k | RIPE NCC |  US | 12th Jun 2012 |
| 5.63.18.0/24 | 256 | RIPE NCC | GB | 15th Jan 2024 |
| 5.63.184.0/24 | 256 | RIPE NCC | CZ | 13th Jun 2012 |
| 5.63.190.0/24 | 256 | RIPE NCC | PL | 13th Jun 2012 |
| 5.73.0.0/16 | 65.5k | RIPE NCC | IR | 11th Jun 2012 |
| 5.8.251.0/24 | 256 | RIPE NCC | US | 26th May 2021 |
| 5.8.88.0/22 | 1k | RIPE NCC |  RU | 25th Apr 2012 |
| 50.115.28.0/22 | 1k | ARIN | US | 20th May 2026 |
| 50.115.48.0/20 | 4.1k | ARIN | US | 9th Sept 2011 |
| 50.116.192.0/18 | 16.4k | ARIN | US | 3rd Oct 2011 |
| 50.118.0.0/17 | 32.8k | ARIN | US | 3rd Nov 2011 |
| 50.93.128.0/20 | 4.1k | ARIN | US | 7th Feb 2011 |
| 50.93.192.0/20 | 4.1k | ARIN | US | 8th Feb 2011 |
| 51.100.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 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 |
| 51.164.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |