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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 States
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 165.140.104.0/24 | 256 | ARIN |  US | 11th Apr 2024 |
| 165.140.136.0/22 | 1k | ARIN | US | 2nd Dec 2021 |
| 165.140.188.0/24 | 256 | ARIN | US | 4th Nov 2021 |
| 165.140.4.0/22 | 1k | ARIN | US | 6th Jan 2022 |
| 165.140.52.0/24 | 256 | ARIN | US | 23rd Dec 2024 |
| 165.140.57.0/24 | 256 | ARIN | US | 2nd Apr 2026 |
| 165.140.80.0/22 | 1k | ARIN | US | 6th Jan 2022 |
| 165.153.0.0/16 | 65.5k | ARIN | US | 17th Jun 1993 |
| 165.157.0.0/16 | 65.5k | ARIN | US | 21st Jun 1993 |
| 165.163.0.0/16 | 65.5k | ARIN | US | 25th Jun 1993 |
| 165.164.0.0/16 | 65.5k | ARIN | US | 28th Jun 1993 |
| 165.167.0.0/16 | 65.5k | ARIN | US | 11th Sept 2018 |
| 165.168.0.0/16 | 65.5k | ARIN | US | 6th Jul 1993 |
| 165.172.0.0/16 | 65.5k | ARIN | US | 8th Jul 1993 |
| 165.174.0.0/16 | 65.5k | ARIN | US | 12th Jul 1993 |
| 165.176.0.0/16 | 65.5k | ARIN | US | 19th Jul 1993 |
| 165.177.0.0/16 | 65.5k | ARIN | US | 19th Jul 1993 |
| 165.179.0.0/16 | 65.5k | ARIN | US | 21st Jul 1993 |
| 165.188.0.0/18 | 16.4k | ARIN | US | 27th Aug 1993 |
| 165.198.0.0/16 | 65.5k | ARIN | US | 16th Aug 1993 |
| 165.2.0.0/18 | 16.4k | ARIN | US | 24th Mar 1993 |
| 165.2.88.0/21 | 2k | ARIN | US | 24th Mar 1993 |
| 165.203.0.0/16 | 65.5k | ARIN | US | 25th Aug 1993 |
| 165.217.144.0/20 | 4.1k | ARIN | US | 7th Sept 1993 |
| 165.217.64.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.68.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.72.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.76.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.80.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.84.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.88.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.217.92.0/22 | 1k | RIPE NCC | US | 7th Sept 1993 |
| 165.238.0.0/16 | 65.5k | ARIN | US | 1st Oct 1993 |
| 165.28.0.0/16 | 65.5k | ARIN | US | 6th Apr 1993 |
| 165.30.0.0/16 | 65.5k | ARIN | US | 8th Apr 1993 |
| 165.32.0.0/13 | 524k | ARIN | US | 11th Feb 1993 |
| 165.40.0.0/15 | 131k | ARIN | US | 11th Feb 1993 |
| 165.44.0.0/14 | 262k | ARIN | US | 11th Feb 1993 |
| 165.48.0.0/16 | 65.5k | ARIN | US | 11th Feb 1993 |
| 165.64.0.0/16 | 65.5k | ARIN | US | 9th Apr 1993 |
| 165.7.0.0/16 | 65.5k | ARIN | US | 26th Mar 1993 |
| 165.71.0.0/16 | 65.5k | ARIN | US | 15th Apr 1993 |
| 165.77.0.0/16 | 65.5k | ARIN | US | 22nd Apr 1993 |
| 165.80.0.0/16 | 65.5k | ARIN | US | 26th Apr 1993 |
| 165.99.124.0/23 | 512 | APNIC | US | 26th May 2025 |
| 166.10.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 166.101.0.0/16 | 65.5k | ARIN | US | 30th Nov 1993 |
| 166.105.0.0/16 | 65.5k | ARIN | US | 3rd Dec 1993 |
| 166.108.32.0/19 | 8.2k | ARIN | US | 6th Dec 1993 |
| 166.11.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |