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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,295 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 23.191.56.0/24 | 256 | ARIN |  US | 7th Oct 2024 |
| 23.226.144.0/20 | 4.1k | ARIN | US | 20th Sept 2013 |
| 23.227.0.0/19 | 8.2k | ARIN | US | 16th Sept 2013 |
| 23.228.0.0/18 | 16.4k | ARIN | US | 9th Sept 2013 |
| 23.236.32.0/20 | 4.1k | ARIN | US | 18th Oct 2013 |
| 23.246.132.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.152.0/22 | 1k | ARIN | US | 6th Jul 2026 |
| 23.246.160.0/23 | 512 | ARIN | US | 6th Jul 2026 |
| 23.246.162.0/23 | 512 | ARIN | US | 7th Jul 2026 |
| 23.246.172.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.176.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 23.246.192.0/18 | 16.4k | ARIN | US | 14th Nov 2013 |
| 23.247.140.0/22 | 1k | ARIN | US | 7th Oct 2021 |
| 23.247.184.0/23 | 512 | ARIN | US | 20th Oct 2021 |
| 23.247.186.0/24 | 256 | ARIN | US | 8th Oct 2021 |
| 23.247.190.0/24 | 256 | ARIN | US | 5th Oct 2021 |
| 23.247.224.0/22 | 1k | ARIN | US | 8th Oct 2021 |
| 23.247.244.0/22 | 1k | ARIN | US | 8th Oct 2021 |
| 23.247.254.0/23 | 512 | ARIN | US | 10th Nov 2021 |
| 23.249.144.0/20 | 4.1k | ARIN | US | 28th Sept 2018 |
| 23.249.166.0/24 | 256 | ARIN | US | 10th Mar 2020 |
| 23.29.160.0/19 | 8.2k | ARIN | US | 26th Mar 2012 |
| 23.88.224.0/19 | 8.2k | ARIN | US | 14th Apr 2021 |
| 23.92.96.0/20 | 4.1k | ARIN | US | 20th Aug 2013 |
| 24.110.10.0/24 | 256 | ARIN | US | 23rd Mar 2004 |
| 24.110.11.0/24 | 256 | ARIN | US | 19th Nov 2024 |
| 24.110.12.0/22 | 1k | ARIN | US | 19th Nov 2024 |
| 24.136.64.0/19 | 8.2k | ARIN | US | 13th Sept 2001 |
| 24.143.224.0/19 | 8.2k | ARIN | US | 26th Feb 2007 |
| 24.149.128.0/17 | 32.8k | ARIN | US | 21st Jan 2004 |
| 24.157.0.0/20 | 4.1k | ARIN | US | 20th Nov 2007 |
| 24.170.208.0/20 | 4.1k | ARIN | US | 10th Sept 2007 |
| 24.171.128.0/19 | 8.2k | ARIN | US | 27th Jun 2002 |
| 24.194.0.0/15 | 131k | ARIN | US | 11th Jul 2002 |
| 24.214.184.0/24 | 256 | ARIN | US | 15th Apr 1999 |
| 24.214.186.0/24 | 256 | ARIN | US | 15th Apr 1999 |
| 24.221.0.0/16 | 65.5k | ARIN | US | 8th Dec 1998 |
| 24.223.81.0/24 | 256 | ARIN | US | 2nd Sept 2014 |
| 24.224.54.0/24 | 256 | ARIN | US | 29th Jan 2007 |
| 24.224.57.0/24 | 256 | ARIN | US | 29th Jan 2007 |
| 24.225.32.0/19 | 8.2k | ARIN | US | 28th Aug 2003 |
| 24.225.64.0/19 | 8.2k | ARIN | US | 28th Aug 2003 |
| 24.233.32.0/19 | 8.2k | ARIN | US | 2nd Aug 2002 |
| 24.235.64.0/21 | 2k | ARIN | US | 2nd Sept 2005 |
| 24.236.0.0/19 | 8.2k | ARIN | US | 13th Oct 1997 |
| 24.31.64.0/18 | 16.4k | ARIN | US | 2nd Mar 1999 |
| 24.40.192.0/19 | 8.2k | ARIN | US | 16th Sept 2005 |
| 24.48.160.0/24 | 256 | ARIN | US | 22nd Oct 2008 |
| 24.50.128.0/20 | 4.1k | ARIN | US | 22nd May 2009 |
| 24.50.144.0/20 | 4.1k | ARIN | US | 28th Oct 2009 |