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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.201.230.0/24 | 256 | ARIN |  US | 5th May 1994 |
| 199.201.231.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.232.0/22 | 1k | ARIN | US | 5th May 1994 |
| 199.201.238.0/24 | 256 | ARIN | US | 2nd May 1994 |
| 199.201.239.0/24 | 256 | ARIN | US | 2nd May 1994 |
| 199.201.24.0/23 | 512 | ARIN | US | 18th Mar 1994 |
| 199.201.240.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.241.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.244.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.246.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.247.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.250.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.251.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.252.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.253.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.254.0/24 | 256 | ARIN | US | 5th May 1994 |
| 199.201.26.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.201.27.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.201.28.0/22 | 1k | ARIN | US | 18th Mar 1994 |
| 199.201.8.0/21 | 2k | ARIN | US | 28th Apr 1994 |
| 199.202.240.0/20 | 4.1k | ARIN | US | 14th Jun 1994 |
| 199.204.104.0/22 | 1k | ARIN | US | 19th Apr 2010 |
| 199.204.144.0/21 | 2k | ARIN | US | 22nd Apr 2010 |
| 199.204.28.0/22 | 1k | ARIN | US | 5th Apr 2010 |
| 199.204.94.0/24 | 256 | ARIN | US | 22nd Jan 2020 |
| 199.21.0.0/21 | 2k | ARIN | US | 8th Oct 1993 |
| 199.21.116.0/22 | 1k | ARIN | US | 14th Oct 2011 |
| 199.21.12.0/23 | 512 | ARIN | US | 8th Oct 1993 |
| 199.21.14.0/24 | 256 | ARIN | US | 8th Oct 1993 |
| 199.21.8.0/22 | 1k | ARIN | US | 8th Oct 1993 |
| 199.212.14.0/24 | 256 | ARIN | US | 4th May 2012 |
| 199.212.220.0/22 | 1k | ARIN | US | 23rd Mar 1994 |
| 199.212.56.0/24 | 256 | ARIN | US | 4th May 2012 |
| 199.212.63.0/24 | 256 | ARIN | US | 21st Sept 2016 |
| 199.212.86.0/23 | 512 | ARIN | US | 21st Jul 2015 |
| 199.217.100.0/24 | 256 | ARIN | US | 14th Aug 2026 |
| 199.217.101.0/24 | 256 | ARIN | US | 20th Aug 2026 |
| 199.217.16.0/20 | 4.1k | ARIN | US | 24th Mar 1994 |
| 199.217.8.0/21 | 2k | ARIN | US | 6th Apr 1994 |
| 199.223.0.0/20 | 4.1k | ARIN | US | 30th Mar 1994 |
| 199.223.116.0/22 | 1k | ARIN | US | 22nd Jun 2012 |
| 199.223.192.0/20 | 4.1k | ARIN | US | 28th Apr 1994 |
| 199.223.96.0/20 | 4.1k | ARIN | US | 10th May 1994 |
| 199.229.192.0/20 | 4.1k | ARIN | US | 6th Apr 1994 |
| 199.230.0.0/21 | 2k | ARIN | US | 11th Apr 1994 |
| 199.230.30.0/23 | 512 | ARIN | US | 15th Jul 2015 |
| 199.230.32.0/20 | 4.1k | ARIN | US | 15th Feb 1994 |
| 199.230.48.0/22 | 1k | ARIN | US | 15th Feb 1994 |
| 199.230.64.0/19 | 8.2k | ARIN | US | 19th May 1994 |
| 199.230.8.0/23 | 512 | ARIN | US | 11th Apr 1994 |