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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
26,963 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 64.250.144.0/20 | 4.1k | ARIN |  US | 24th Sept 2009 |
| 64.252.128.0/18 | 16.4k | ARIN | US | 10th Jan 2018 |
| 64.253.192.0/20 | 4.1k | ARIN | US | 22nd Jan 2001 |
| 64.253.224.0/19 | 8.2k | ARIN | US | 22nd Jan 2001 |
| 64.254.80.0/21 | 2k | ARIN | US | 26th May 2004 |
| 64.255.15.0/24 | 256 | ARIN | US | 16th Jan 2001 |
| 64.255.24.0/24 | 256 | ARIN | US | 16th Oct 2026 |
| 64.255.41.0/24 | 256 | ARIN | US | 16th Jan 2001 |
| 64.255.43.0/24 | 256 | ARIN | US | 16th Jan 2001 |
| 64.255.46.0/24 | 256 | ARIN | US | 16th Jan 2001 |
| 64.255.52.0/23 | 512 | ARIN | US | 12th Jan 2026 |
| 64.255.55.0/24 | 256 | ARIN | US | 16th Jan 2001 |
| 64.27.0.0/19 | 8.2k | ARIN | US | 9th Aug 2023 |
| 64.28.168.0/22 | 1k | ARIN | US | 6th Oct 2025 |
| 64.28.172.0/22 | 1k | ARIN | US | 17th Oct 2025 |
| 64.28.176.0/20 | 4.1k | ARIN | US | 12th Jun 2013 |
| 64.28.238.0/24 | 256 | ARIN | US | 26th Apr 2021 |
| 64.28.42.0/24 | 256 | ARIN | US | 4th Jun 2026 |
| 64.29.192.0/19 | 8.2k | ARIN | US | 7th Feb 2000 |
| 64.30.152.0/23 | 512 | ARIN | US | 8th Nov 2021 |
| 64.30.156.0/23 | 512 | ARIN | US | 4th Oct 2021 |
| 64.30.160.0/19 | 8.2k | ARIN | US | 24th Apr 2001 |
| 64.32.42.0/24 | 256 | ARIN | US | 14th Apr 2020 |
| 64.32.51.0/24 | 256 | ARIN | US | 14th Apr 2020 |
| 64.35.128.0/20 | 4.1k | ARIN | US | 18th Apr 2001 |
| 64.39.231.0/24 | 256 | ARIN | US | 10th Apr 2024 |
| 64.39.67.0/24 | 256 | ARIN | US | 12th Dec 2023 |
| 64.40.10.0/24 | 256 | ARIN | US | 15th Sept 2025 |
| 64.40.192.0/22 | 1k | ARIN | US | 26th Jun 2024 |
| 64.40.196.0/22 | 1k | ARIN | US | 26th Jun 2024 |
| 64.40.24.0/22 | 1k | ARIN | US | 26th Mar 2020 |
| 64.40.28.0/22 | 1k | ARIN | US | 26th Mar 2020 |
| 64.49.30.0/23 | 512 | ARIN | US | 26th Jun 2024 |
| 64.49.4.0/22 | 1k | ARIN | US | 26th Jun 2024 |
| 64.49.51.0/24 | 256 | ARIN | US | 8th Jul 2024 |
| 64.49.52.0/22 | 1k | ARIN | US | 23rd Aug 2024 |
| 64.5.113.0/24 | 256 | ARIN | US | 6th Sept 2018 |
| 64.5.118.0/24 | 256 | ARIN | US | 15th Oct 2018 |
| 64.52.0.0/23 | 512 | ARIN | US | 6th Mar 2000 |
| 64.52.10.0/24 | 256 | ARIN | US | 6th Mar 2000 |
| 64.52.105.0/24 | 256 | ARIN | US | 5th Nov 2024 |
| 64.52.15.0/24 | 256 | ARIN | US | 6th Mar 2000 |
| 64.52.162.0/23 | 512 | ARIN | US | 14th May 2021 |
| 64.52.2.0/24 | 256 | ARIN | US | 24th Jan 2025 |
| 64.52.20.0/24 | 256 | ARIN | US | 6th Mar 2000 |
| 64.52.22.0/23 | 512 | ARIN | US | 14th May 2021 |
| 64.52.3.0/24 | 256 | ARIN | US | 3rd Jun 2021 |
| 64.52.84.0/22 | 1k | ARIN | US | 14th May 2021 |
| 64.52.88.0/21 | 2k | ARIN | US | 22nd Sept 2020 |
| 64.56.222.0/23 | 512 | ARIN | US | 7th Jul 2022 |