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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,041 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 161.36.0.0/18 | 16.4k | ARIN |  US | 14th May 1992 |
| 161.36.120.0/21 | 2k | ARIN | US | 14th May 1992 |
| 161.36.128.0/17 | 32.8k | ARIN | US | 14th May 1992 |
| 161.36.96.0/21 | 2k | ARIN | US | 14th May 1992 |
| 161.38.252.0/23 | 512 | ARIN | US | 24th Jul 2024 |
| 161.38.64.0/18 | 16.4k | RIPE NCC |  DE | 14th May 1992 |
| 161.48.0.0/16 | 65.5k | RIPE NCC |  FR | 20th May 1992 |
| 161.49.188.0/22 | 1k | ARIN | US | 21st May 1992 |
| 161.51.100.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.51.102.0/23 | 512 | ARIN | US | 27th May 1992 |
| 161.51.104.0/21 | 2k | ARIN | US | 27th May 1992 |
| 161.51.112.0/20 | 4.1k | ARIN | US | 27th May 1992 |
| 161.51.254.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.51.98.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.59.0.0/16 | 65.5k | RIPE NCC |  BE | 2nd Jun 1992 |
| 161.60.0.0/16 | 65.5k | ARIN | US | 3rd Jun 1992 |
| 161.63.0.0/16 | 65.5k | ARIN | US | 9th Jun 1992 |
| 161.75.0.0/16 | 65.5k | APNIC |  JP | 13th Mar 1996 |
| 161.83.0.0/16 | 65.5k | RIPE NCC |  NL | 23rd Jun 1992 |
| 161.84.0.0/15 | 131k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.86.0.0/15 | 131k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.88.0.0/16 | 65.5k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.90.0.0/16 | 65.5k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.91.0.0/16 | 65.5k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.92.0.0/16 | 65.5k | RIPE NCC | NL | 23rd Jun 1992 |
| 161.93.0.0/16 | 65.5k | APNIC | JP | 23rd Jun 1992 |
| 161.94.0.0/15 | 131k | APNIC | JP | 23rd Jun 1992 |
| 161.96.0.0/16 | 65.5k | APNIC | JP | 23rd Jun 1992 |
| 161.99.0.0/17 | 32.8k | ARIN | US | 23rd Jun 1992 |
| 162.0.0.0/17 | 32.8k | ARIN |  CA | 14th Jan 2013 |
| 162.0.144.0/21 | 2k | ARIN | CA | 14th Jan 2013 |
| 162.0.248.0/21 | 2k | ARIN | CA | 14th Jan 2013 |
| 162.100.0.0/14 | 262k | ARIN | US | 28th Sept 1992 |
| 162.109.0.0/16 | 65.5k | ARIN | US | 7th Oct 1992 |
| 162.110.0.0/16 | 65.5k | ARIN | US | 13th Oct 1992 |
| 162.113.0.0/16 | 65.5k | ARIN | US | 15th Oct 1992 |
| 162.118.128.0/17 | 32.8k | ARIN | US | 21st Sept 2020 |
| 162.12.0.0/17 | 32.8k | ARIN | US | 30th Jun 1992 |
| 162.12.128.0/18 | 16.4k | ARIN | US | 30th Jun 1992 |
| 162.12.192.0/22 | 1k | ARIN | US | 30th Jun 1992 |
| 162.12.232.0/22 | 1k | ARIN | US | 18th Apr 2017 |
| 162.12.240.0/22 | 1k | APNIC |  AU | 13th Dec 2018 |
| 162.12.248.0/21 | 2k | ARIN | US | 10th May 2012 |
| 162.120.20.0/24 | 256 | ARIN | US | 12th Jan 2023 |
| 162.120.40.0/22 | 1k | ARIN | US | 14th Mar 2025 |
| 162.120.44.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.120.48.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.120.72.0/23 | 512 | ARIN | US | 21st Jun 2023 |
| 162.120.80.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.122.0.0/16 | 65.5k | LACNIC |  VE | 6th Nov 1992 |