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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.254.230.0/24 | 256 | ARIN |  US | 3rd Nov 1994 |
| 199.254.231.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.232.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.233.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.234.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.237.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.239.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.24.0/23 | 512 | ARIN | US | 5th May 1994 |
| 199.254.240.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 199.254.241.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.242.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.243.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.244.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.245.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.246.0/24 | 256 | ARIN | US | 4th Nov 1994 |
| 199.254.248.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.249.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.250.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.251.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.252.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.254.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.255.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 199.254.27.0/24 | 256 | ARIN | US | 11th Feb 2010 |
| 199.254.32.0/20 | 4.1k | ARIN | US | 9th May 1994 |
| 199.254.96.0/21 | 2k | ARIN | US | 15th Aug 2012 |
| 199.255.124.0/22 | 1k | ARIN | US | 20th May 2010 |
| 199.255.128.0/21 | 2k | ARIN | US | 19th May 2010 |
| 199.255.196.0/22 | 1k | ARIN | US | 2nd Jun 2010 |
| 199.255.232.0/22 | 1k | ARIN | US | 7th Jun 2010 |
| 199.255.236.0/22 | 1k | ARIN | US | 8th Jun 2010 |
| 199.255.4.0/22 | 1k | ARIN | US | 7th May 2010 |
| 199.255.56.0/22 | 1k | ARIN | US | 18th Dec 2018 |
| 199.255.60.0/22 | 1k | ARIN | US | 30th May 2012 |
| 199.26.0.0/21 | 2k | ARIN | US | 15th Oct 1993 |
| 199.26.132.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.137.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.138.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.139.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.140.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.141.0/24 | 256 | ARIN | US | 28th Dec 1993 |
| 199.26.142.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.143.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.144.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.145.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.146.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.147.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.148.0/23 | 512 | ARIN | US | 29th Dec 1993 |
| 199.26.153.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.154.0/24 | 256 | ARIN | US | 29th Dec 1993 |
| 199.26.155.0/24 | 256 | ARIN | US | 30th Dec 1993 |