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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,300 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 206.221.0.0/20 | 4.1k | ARIN |  US | 25th Sept 1995 |
| 206.221.192.0/20 | 4.1k | ARIN | US | 5th Mar 1996 |
| 206.221.64.0/20 | 4.1k | ARIN | US | 10th Oct 1995 |
| 206.221.96.0/20 | 4.1k | ARIN | US | 11th Oct 1995 |
| 206.222.128.0/19 | 8.2k | ARIN | US | 10th May 1996 |
| 206.223.0.0/24 | 256 | ARIN | US | 6th Oct 1995 |
| 206.223.1.0/24 | 256 | ARIN | US | 6th Oct 1995 |
| 206.223.10.0/24 | 256 | ARIN | US | 9th Oct 1995 |
| 206.223.100.0/24 | 256 | ARIN | US | 14th Aug 1996 |
| 206.223.101.0/24 | 256 | ARIN | US | 13th Dec 1996 |
| 206.223.102.0/24 | 256 | ARIN | US | 3rd Feb 1997 |
| 206.223.104.0/22 | 1k | ARIN | US | 4th Sept 1996 |
| 206.223.11.0/24 | 256 | ARIN | US | 9th Oct 1995 |
| 206.223.110.0/24 | 256 | ARIN | US | 9th Sept 1996 |
| 206.223.115.0/24 | 256 | ARIN | US | 20th Jul 1999 |
| 206.223.116.0/24 | 256 | ARIN | US | 25th May 2000 |
| 206.223.117.0/24 | 256 | ARIN | US | 30th May 2000 |
| 206.223.118.0/24 | 256 | ARIN | US | 15th Jun 2001 |
| 206.223.119.0/24 | 256 | ARIN | US | 4th Mar 2002 |
| 206.223.12.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.120.0/23 | 512 | ARIN | US | 4th Aug 2009 |
| 206.223.125.0/24 | 256 | ARIN | US | 22nd Oct 2012 |
| 206.223.128.0/24 | 256 | ARIN | US | 20th Jun 2025 |
| 206.223.13.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.131.0/24 | 256 | ARIN | US | 11th Mar 2003 |
| 206.223.137.0/24 | 256 | ARIN | US | 31st Oct 2002 |
| 206.223.138.0/24 | 256 | ARIN | US | 28th Jan 2004 |
| 206.223.14.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.140.0/24 | 256 | ARIN | US | 5th Aug 2004 |
| 206.223.141.0/24 | 256 | ARIN | US | 20th Aug 2004 |
| 206.223.142.0/24 | 256 | ARIN | US | 31st Aug 2004 |
| 206.223.15.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.16.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.19.0/24 | 256 | ARIN | US | 10th Oct 1995 |
| 206.223.2.0/24 | 256 | ARIN | US | 6th Oct 1995 |
| 206.223.20.0/24 | 256 | ARIN | US | 11th Oct 1995 |
| 206.223.22.0/24 | 256 | ARIN | US | 11th Oct 1995 |
| 206.223.23.0/24 | 256 | ARIN | US | 12th Oct 1995 |
| 206.223.24.0/24 | 256 | ARIN | US | 12th Oct 1995 |
| 206.223.26.0/24 | 256 | ARIN | US | 13th Oct 1995 |
| 206.223.27.0/24 | 256 | ARIN | US | 13th Oct 1995 |
| 206.223.28.0/24 | 256 | ARIN | US | 13th Oct 1995 |
| 206.223.29.0/24 | 256 | ARIN | US | 13th Oct 1995 |
| 206.223.3.0/24 | 256 | ARIN | US | 6th Oct 1995 |
| 206.223.31.0/24 | 256 | ARIN | US | 16th Oct 1995 |
| 206.223.32.0/24 | 256 | ARIN | US | 16th Oct 1995 |
| 206.223.33.0/24 | 256 | ARIN | US | 17th Oct 1995 |
| 206.223.34.0/24 | 256 | ARIN | US | 17th Oct 1995 |
| 206.223.35.0/24 | 256 | ARIN | US | 17th Oct 1995 |
| 206.223.37.0/24 | 256 | ARIN | US | 18th Oct 1995 |