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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.19.8.0/21 | 2k | ARIN |  US | 4th Oct 1993 |
| 199.19.84.0/22 | 1k | ARIN | US | 7th Oct 2011 |
| 199.190.130.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 199.190.132.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 199.190.133.0/24 | 256 | ARIN | US | 11th May 2012 |
| 199.190.135.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.141.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.142.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.143.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.144.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.145.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.146.0/23 | 512 | ARIN | US | 21st Apr 1994 |
| 199.190.148.0/23 | 512 | ARIN | US | 21st Apr 1994 |
| 199.190.150.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.156.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.157.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.158.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.16.0/20 | 4.1k | ARIN | US | 1st Mar 1994 |
| 199.190.165.0/24 | 256 | ARIN | US | 17th May 2012 |
| 199.190.166.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.167.0/24 | 256 | ARIN | US | 27th Aug 2019 |
| 199.190.168.0/24 | 256 | ARIN | US | 23rd May 2012 |
| 199.190.169.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.170.0/23 | 512 | ARIN | US | 22nd Apr 1994 |
| 199.190.172.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.173.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.176.0/23 | 512 | ARIN | US | 25th Apr 1994 |
| 199.190.178.0/23 | 512 | ARIN | US | 25th Apr 1994 |
| 199.190.180.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.181.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.182.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.186.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.187.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.188.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.189.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 199.190.190.0/24 | 256 | ARIN | US | 26th Apr 1994 |
| 199.190.192.0/24 | 256 | ARIN | US | 26th Apr 1994 |
| 199.190.193.0/24 | 256 | ARIN | US | 26th Apr 1994 |
| 199.190.194.0/23 | 512 | ARIN | US | 20th Jul 2015 |
| 199.190.198.0/23 | 512 | ARIN | US | 27th Apr 1994 |
| 199.190.200.0/24 | 256 | ARIN | US | 27th Apr 1994 |
| 199.190.201.0/24 | 256 | ARIN | US | 27th Apr 1994 |
| 199.190.202.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.203.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.204.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.205.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.206.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.207.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.208.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 199.190.209.0/24 | 256 | ARIN | US | 17th Sept 2015 |