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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,954 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 5.44.255.0/24 | 256 | RIPE NCC |  US | 30th Jul 2021 |
| 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 |
| 5.8.240.0/21 | 2k | RIPE NCC |  IQ | 26th Apr 2012 |
| 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 |
| 51.166.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.18.0.0/16 | 65.5k | RIPE NCC | DE | 1st Sept 1993 |
| 51.2.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.202.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.204.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.206.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.226.0.0/15 | 131k | RIPE NCC | US | 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 |
| 51.250.128.0/17 | 32.8k | RIPE NCC | RU | 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 |
| 51.62.0.0/15 | 131k | RIPE NCC | GB | 1st Sept 1993 |
| 51.65.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 51.66.0.0/15 | 131k | RIPE NCC | GB | 1st Sept 1993 |
| 51.71.0.0/16 | 65.5k | RIPE NCC | GB | 1st Sept 1993 |
| 52.119.0.0/24 | 256 | ARIN | US | 27th Apr 2016 |
| 52.119.1.0/24 | 256 | ARIN | US | 28th Aug 2017 |
| 52.119.13.0/24 | 256 | ARIN | US | 1st Jun 2016 |