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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,346 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 23.147.32.0/24 | 256 | ARIN |  US | 29th Aug 2018 |
| 23.147.80.0/24 | 256 | ARIN |  CA | 13th Dec 2019 |
| 23.148.0.0/24 | 256 | ARIN | US | 9th Dec 2015 |
| 23.148.100.0/24 | 256 | ARIN | US | 27th Oct 2025 |
| 23.148.148.0/24 | 256 | ARIN | US | 29th Oct 2025 |
| 23.148.156.0/24 | 256 | ARIN | US | 29th Oct 2025 |
| 23.148.168.0/24 | 256 | ARIN | US | 27th Feb 2023 |
| 23.148.172.0/24 | 256 | ARIN | US | 29th Oct 2025 |
| 23.148.192.0/24 | 256 | ARIN | CA | 27th Oct 2017 |
| 23.148.193.0/24 | 256 | ARIN | CA | 2nd Jan 2019 |
| 23.148.194.0/24 | 256 | ARIN | CA | 18th Mar 2020 |
| 23.148.195.0/24 | 256 | ARIN | CA | 25th Sept 2020 |
| 23.148.40.0/24 | 256 | ARIN | US | 15th Feb 2023 |
| 23.149.132.0/24 | 256 | ARIN | US | 13th Nov 2025 |
| 23.149.152.0/24 | 256 | ARIN | CA | 15th Mar 2023 |
| 23.149.164.0/24 | 256 | ARIN | US | 13th Nov 2025 |
| 23.149.188.0/24 | 256 | ARIN | US | 14th Nov 2025 |
| 23.149.200.0/24 | 256 | ARIN | US | 16th Mar 2023 |
| 23.149.220.0/24 | 256 | ARIN | US | 18th Nov 2025 |
| 23.149.252.0/24 | 256 | ARIN | US | 20th Nov 2025 |
| 23.149.40.0/24 | 256 | ARIN | CA | 8th Mar 2023 |
| 23.149.56.0/24 | 256 | ARIN | US | 9th Mar 2023 |
| 23.149.84.0/24 | 256 | ARIN | US | 20th Feb 2026 |
| 23.150.112.0/24 | 256 | ARIN | US | 10th Feb 2020 |
| 23.150.124.0/24 | 256 | ARIN | CA | 25th Nov 2025 |
| 23.150.168.0/24 | 256 | ARIN | US | 5th Apr 2023 |
| 23.150.180.0/24 | 256 | ARIN | US | 3rd Dec 2025 |
| 23.150.240.0/24 | 256 | ARIN |  PR | 18th Feb 2020 |
| 23.150.33.0/24 | 256 | ARIN | US | 19th Jul 2019 |
| 23.150.4.0/24 | 256 | ARIN | US | 21st Nov 2025 |
| 23.150.48.0/24 | 256 | ARIN | US | 10th Feb 2020 |
| 23.150.64.0/24 | 256 | ARIN | US | 2nd Nov 2017 |
| 23.150.72.0/24 | 256 | ARIN | US | 24th Mar 2023 |
| 23.150.92.0/24 | 256 | ARIN | US | 25th Nov 2025 |
| 23.151.120.0/24 | 256 | ARIN | US | 20th Apr 2023 |
| 23.151.140.0/24 | 256 | ARIN | CA | 19th Dec 2025 |
| 23.151.172.0/24 | 256 | ARIN | US | 19th Dec 2025 |
| 23.151.180.0/24 | 256 | ARIN | US | 24th Dec 2025 |
| 23.151.228.0/24 | 256 | ARIN | US | 24th Dec 2025 |
| 23.151.233.0/24 | 256 | ARIN | US | 3rd Nov 2023 |
| 23.151.248.0/24 | 256 | ARIN | US | 26th Apr 2023 |
| 23.151.40.0/24 | 256 | ARIN | US | 13th Apr 2023 |
| 23.151.44.0/24 | 256 | ARIN | US | 17th Dec 2025 |
| 23.151.64.0/24 | 256 | ARIN | US | 3rd Nov 2017 |
| 23.152.148.0/24 | 256 | ARIN | US | 26th Feb 2026 |
| 23.152.168.0/24 | 256 | ARIN | US | 16th May 2023 |
| 23.152.193.0/24 | 256 | ARIN | US | 3rd Aug 2018 |
| 23.152.194.0/24 | 256 | ARIN | US | 30th Sept 2021 |
| 23.152.196.0/24 | 256 | ARIN | US | 27th Feb 2026 |
| 23.152.225.0/24 | 256 | ARIN | US | 14th Jun 2019 |