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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,273 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 63.251.230.0/23 | 512 | ARIN |  US | 2nd Dec 1999 |
| 64.110.152.0/24 | 256 | ARIN | US | 19th Jun 2000 |
| 64.110.48.0/23 | 512 | ARIN | US | 11th Jul 2022 |
| 64.111.192.0/19 | 8.2k | ARIN | US | 9th Mar 2005 |
| 64.111.36.0/24 | 256 | ARIN | US | 3rd Mar 2005 |
| 64.111.44.0/24 | 256 | ARIN | US | 3rd Mar 2005 |
| 64.111.58.0/23 | 512 | ARIN | US | 3rd Mar 2005 |
| 64.112.112.0/22 | 1k | ARIN | US | 1st Jul 2021 |
| 64.112.117.0/24 | 256 | ARIN | US | 2nd Jul 2021 |
| 64.112.13.0/24 | 256 | ARIN | US | 6th Apr 2021 |
| 64.112.15.0/24 | 256 | ARIN | US | 28th Apr 2021 |
| 64.112.64.0/24 | 256 | ARIN | US | 31st Aug 2021 |
| 64.112.65.0/24 | 256 | ARIN | US | 3rd Oct 2024 |
| 64.112.72.0/22 | 1k | ARIN | US | 1st Jul 2021 |
| 64.118.51.0/24 | 256 | ARIN | US | 22nd Mar 2024 |
| 64.118.52.0/24 | 256 | ARIN | US | 22nd Mar 2024 |
| 64.119.224.0/20 | 4.1k | ARIN | US | 23rd Aug 2001 |
| 64.119.240.0/20 | 4.1k | ARIN | US | 28th Aug 2001 |
| 64.120.109.0/24 | 256 | ARIN | US | 24th Apr 2009 |
| 64.127.196.0/22 | 1k | ARIN | US | 26th Feb 2021 |
| 64.133.0.0/16 | 65.5k | ARIN | US | 19th Jul 2000 |
| 64.142.128.0/17 | 32.8k | ARIN | US | 22nd May 2002 |
| 64.145.76.0/24 | 256 | ARIN | US | 21st Jan 2009 |
| 64.150.162.0/24 | 256 | ARIN | US | 8th Sept 2006 |
| 64.16.112.0/22 | 1k | ARIN | US | 2nd Apr 2026 |
| 64.16.124.0/22 | 1k | ARIN | US | 2nd Apr 2026 |
| 64.16.64.0/19 | 8.2k | ARIN | US | 17th Aug 2004 |
| 64.16.96.0/20 | 4.1k | ARIN | US | 29th Jun 2004 |
| 64.17.128.0/18 | 16.4k | ARIN | US | 28th May 2004 |
| 64.179.240.0/20 | 4.1k | ARIN | US | 26th Jun 2008 |
| 64.18.128.0/21 | 2k | ARIN | US | 24th Aug 2004 |
| 64.185.64.0/19 | 8.2k | ARIN | US | 30th Jul 2001 |
| 64.186.0.0/23 | 512 | ARIN | US | 18th Jul 2019 |
| 64.186.11.0/24 | 256 | ARIN | US | 14th Aug 2019 |
| 64.186.148.0/22 | 1k | ARIN | US | 27th Jan 2009 |
| 64.186.152.0/21 | 2k | ARIN | US | 27th Jan 2009 |
| 64.186.208.0/20 | 4.1k | ARIN | US | 30th Nov 2005 |
| 64.186.3.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 64.187.100.0/23 | 512 | ARIN | US | 7th Apr 2020 |
| 64.187.127.0/24 | 256 | ARIN | US | 9th Jul 2019 |
| 64.187.98.0/23 | 512 | ARIN | US | 16th Feb 2022 |
| 64.19.224.0/20 | 4.1k | ARIN | US | 29th Aug 2008 |
| 64.190.0.0/23 | 512 | ARIN | US | 31st May 2002 |
| 64.190.103.0/24 | 256 | ARIN | US | 1st Nov 2021 |
| 64.190.136.0/24 | 256 | ARIN | US | 31st May 2002 |
| 64.190.147.0/24 | 256 | ARIN | US | 31st May 2002 |
| 64.190.154.0/24 | 256 | ARIN | US | 15th Sept 2017 |
| 64.190.170.0/24 | 256 | ARIN | US | 31st Aug 2020 |
| 64.190.200.0/24 | 256 | ARIN | US | 31st May 2002 |
| 64.190.202.0/23 | 512 | ARIN | US | 14th May 2021 |