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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
Browse by registry
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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 |
|---|---|---|---|---|
| 198.199.213.0/24 | 256 | ARIN |  US | 15th Mar 1994 |
| 198.199.214.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 198.199.215.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 198.199.216.0/23 | 512 | ARIN | US | 15th Mar 1994 |
| 198.199.218.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 198.199.221.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 198.199.223.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 198.199.226.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 198.199.227.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 198.199.229.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 198.199.230.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.231.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.232.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.234.0/23 | 512 | ARIN | US | 21st Mar 1994 |
| 198.199.236.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.237.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.240.0/23 | 512 | ARIN | US | 21st Mar 1994 |
| 198.199.244.0/23 | 512 | ARIN | US | 21st Mar 1994 |
| 198.199.246.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.248.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.249.0/24 | 256 | ARIN | US | 21st Mar 1994 |
| 198.199.251.0/24 | 256 | ARIN | US | 25th Feb 1994 |
| 198.199.252.0/23 | 512 | ARIN | US | 25th Feb 1994 |
| 198.199.254.0/24 | 256 | ARIN | US | 25th Feb 1994 |
| 198.199.255.0/24 | 256 | ARIN | US | 26th Dec 2012 |
| 198.199.32.0/20 | 4.1k | ARIN | US | 21st Sept 1993 |
| 198.199.4.0/23 | 512 | ARIN | US | 23rd Jun 1993 |
| 198.199.48.0/22 | 1k | ARIN | US | 21st Sept 1993 |
| 198.20.16.0/20 | 4.1k | ARIN | US | 25th Nov 1992 |
| 198.20.208.0/21 | 2k | ARIN | US | 1st Apr 2013 |
| 198.20.8.0/21 | 2k | ARIN | US | 25th Nov 1992 |
| 198.200.12.0/22 | 1k | ARIN | US | 31st Jul 2023 |
| 198.200.128.0/24 | 256 | ARIN | US | 22nd Mar 1994 |
| 198.200.129.0/24 | 256 | ARIN | US | 22nd Mar 1994 |
| 198.200.131.0/24 | 256 | ARIN | US | 22nd Mar 1994 |
| 198.200.133.0/24 | 256 | ARIN | US | 22nd Mar 1994 |
| 198.200.134.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.135.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.136.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.138.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.140.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.141.0/24 | 256 | ARIN | US | 29th Nov 2012 |
| 198.200.142.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.143.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.144.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 198.200.145.0/24 | 256 | ARIN | US | 25th Mar 1994 |
| 198.200.146.0/24 | 256 | ARIN | US | 6th Dec 2019 |
| 198.200.147.0/24 | 256 | ARIN | US | 25th Oct 1994 |
| 198.200.150.0/24 | 256 | ARIN | US | 25th Mar 1994 |
| 198.200.151.0/24 | 256 | ARIN | US | 25th Mar 1994 |