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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 165.99.103.0/24 | 256 | APNIC |  IN | 21st May 2025 |
| 165.99.107.0/24 | 256 | APNIC |  ID | 22nd May 2025 |
| 165.99.110.0/23 | 512 | APNIC | IN | 22nd May 2025 |
| 165.99.12.0/23 | 512 | APNIC | IN | 7th May 2025 |
| 165.99.124.0/23 | 512 | APNIC |  US | 26th May 2025 |
| 165.99.126.0/23 | 512 | APNIC | ID | 26th May 2025 |
| 165.99.140.0/24 | 256 | APNIC | ID | 27th May 2025 |
| 165.99.170.0/23 | 512 | APNIC |  TW | 29th May 2025 |
| 165.99.180.0/24 | 256 | APNIC |  PH | 2nd Jun 2025 |
| 165.99.208.0/23 | 512 | APNIC |  BD | 5th Jun 2025 |
| 165.99.230.0/23 | 512 | APNIC | IN | 9th Jun 2025 |
| 165.99.232.0/23 | 512 | APNIC |  VN | 9th Jun 2025 |
| 165.99.242.0/23 | 512 | APNIC | IN | 11th Jun 2025 |
| 165.99.96.0/23 | 512 | APNIC | VN | 20th 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 |
| 166.103.0.0/16 | 65.5k | APNIC |  KR | 3rd Dec 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 |
| 166.110.0.0/16 | 65.5k | LACNIC |  CL | 7th Dec 1993 |
| 166.112.0.0/16 | 65.5k | ARIN | US | 10th Dec 1993 |
| 166.113.128.0/17 | 32.8k | ARIN | US | 19th May 2021 |
| 166.115.0.0/16 | 65.5k | ARIN | US | 14th Dec 1993 |
| 166.116.0.0/16 | 65.5k | ARIN | US | 14th Dec 1993 |
| 166.118.0.0/16 | 65.5k | APNIC |  JP | 27th Dec 1993 |
| 166.12.0.0/14 | 262k | RIPE NCC |  CH | 1st Sept 1993 |
| 166.124.0.0/16 | 65.5k | ARIN | US | 3rd Jan 1994 |
| 166.126.0.0/16 | 65.5k | ARIN | US | 5th Jan 1994 |
| 166.16.0.0/16 | 65.5k | ARIN | US | 21st Jun 1993 |
| 166.17.0.0/16 | 65.5k | ARIN | US | 21st Jun 1993 |
| 166.178.0.0/16 | 65.5k | ARIN | US | 1st Apr 2025 |
| 166.179.0.0/18 | 16.4k | ARIN | US | 1st Apr 2025 |
| 166.179.104.0/22 | 1k | ARIN | US | 1st Apr 2025 |
| 166.179.108.0/22 | 1k | ARIN | US | 25th Mar 2025 |
| 166.179.112.0/20 | 4.1k | ARIN | US | 25th Mar 2025 |
| 166.179.128.0/17 | 32.8k | ARIN | US | 25th Mar 2025 |
| 166.179.96.0/21 | 2k | ARIN | US | 1st Apr 2025 |
| 166.18.0.0/16 | 65.5k | ARIN | US | 21st Jun 1993 |
| 166.221.0.0/16 | 65.5k | ARIN | US | 7th Apr 2025 |
| 166.222.0.0/15 | 131k | ARIN | US | 7th Apr 2025 |
| 166.228.0.0/15 | 131k | ARIN | US | 7th Apr 2025 |
| 166.231.0.0/16 | 65.5k | ARIN | US | 7th Apr 2025 |
| 166.232.0.0/14 | 262k | ARIN | US | 7th Apr 2025 |
| 166.237.0.0/16 | 65.5k | ARIN | US | 25th Mar 2025 |
| 166.52.0.0/15 | 131k | ARIN | US | 24th Mar 1993 |
| 166.54.0.0/16 | 65.5k | ARIN | US | 24th Mar 1993 |
| 166.55.0.0/16 | 65.5k | ARIN | US | 24th Mar 1993 |
| 166.57.0.0/16 | 65.5k | ARIN | US | 24th Mar 1993 |
| 166.59.0.0/16 | 65.5k | ARIN | US | 24th Mar 1993 |