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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks
84,968 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 148.190.0.0/16 | 65.5k | ARIN |  US | 22nd May 1991 |
| 148.191.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.192.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 148.193.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.194.0.0/16 | 65.5k | ARIN | US | 23rd May 1991 |
| 148.222.158.0/24 | 256 | ARIN | US | 24th Apr 2025 |
| 148.222.188.0/22 | 1k | LACNIC |  MX | 21st Dec 1992 |
| 148.224.16.0/21 | 2k | LACNIC |  PE | 21st May 1993 |
| 148.224.30.0/24 | 256 | LACNIC | MX | 21st May 1993 |
| 148.224.40.0/22 | 1k | LACNIC | MX | 21st May 1993 |
| 148.224.47.0/24 | 256 | LACNIC | MX | 21st May 1993 |
| 148.224.48.0/22 | 1k | ARIN | US | 22nd May 2025 |
| 148.224.52.0/22 | 1k | LACNIC | MX | 21st May 1993 |
| 148.224.61.0/24 | 256 | LACNIC |  GT | 21st May 1993 |
| 148.227.128.0/19 | 8.2k | LACNIC | MX | 26th Dec 1997 |
| 148.227.160.0/23 | 512 | LACNIC | MX | 26th Dec 1997 |
| 148.227.164.0/23 | 512 | LACNIC | MX | 26th Dec 1997 |
| 148.227.166.0/24 | 256 | LACNIC | MX | 26th Dec 1997 |
| 148.227.168.0/23 | 512 | LACNIC | MX | 26th Dec 1997 |
| 148.227.171.0/24 | 256 | LACNIC | MX | 26th Dec 1997 |
| 148.227.172.0/24 | 256 | LACNIC | PE | 26th Dec 1997 |
| 148.227.176.0/20 | 4.1k | LACNIC | MX | 26th Dec 1997 |
| 148.227.192.0/20 | 4.1k | LACNIC | MX | 26th Dec 1997 |
| 148.227.224.0/19 | 8.2k | LACNIC | MX | 26th Dec 1997 |
| 148.242.0.0/16 | 65.5k | LACNIC | MX | 10th Oct 2000 |
| 148.248.0.0/16 | 65.5k | LACNIC | MX | 1st Sept 1994 |
| 148.252.205.0/24 | 256 | RIPE NCC |  RO | 1st Sept 1993 |
| 148.252.251.0/24 | 256 | RIPE NCC | RO | 1st Sept 1993 |
| 148.253.192.0/20 | 4.1k | RIPE NCC |  GB | 1st Sept 1993 |
| 148.50.0.0/16 | 65.5k | ARIN | US | 13th Mar 1991 |
| 148.51.0.0/17 | 32.8k | RIPE NCC |  KY | 13th Mar 1991 |
| 148.52.128.0/19 | 8.2k | RIPE NCC |  AM | 28th Feb 1991 |
| 148.52.160.0/19 | 8.2k | ARIN | US | 9th Sept 2025 |
| 148.54.0.0/16 | 65.5k | RIPE NCC |  DE | 1st Sept 1993 |
| 148.59.114.0/24 | 256 | ARIN | US | 19th Apr 2018 |
| 148.59.115.0/24 | 256 | RIPE NCC |  IE | 8th Apr 1991 |
| 148.59.129.0/24 | 256 | ARIN |  CA | 27th Nov 2023 |
| 148.59.138.0/24 | 256 | ARIN | US | 1st Jun 2026 |
| 148.59.141.0/24 | 256 | ARIN | CA | 1st Jul 2026 |
| 148.59.144.0/24 | 256 | ARIN | US | 12th Apr 2017 |
| 148.59.155.0/24 | 256 | ARIN | US | 5th Feb 2018 |
| 148.59.166.0/23 | 512 | ARIN | US | 8th Dec 2017 |
| 148.59.206.0/23 | 512 | ARIN | US | 8th Aug 2016 |
| 148.59.216.0/23 | 512 | ARIN | CA | 29th Jun 2016 |
| 148.59.232.0/22 | 1k | ARIN | CA | 21st Nov 2025 |
| 148.59.24.0/24 | 256 | ARIN | US | 31st Aug 2020 |
| 148.59.26.0/24 | 256 | ARIN | US | 9th Oct 2020 |
| 148.59.43.0/24 | 256 | ARIN | US | 17th Aug 2018 |
| 148.59.57.0/24 | 256 | APNIC |  JP | 9th Apr 1991 |
| 148.59.92.0/24 | 256 | ARIN | US | 28th May 2020 |