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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,300 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.91.122.0/24 | 256 | ARIN |  US | 9th Jan 1991 |
| 192.91.123.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.124.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.125.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.126.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.127.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.128.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.129.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.130.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.131.0/24 | 256 | ARIN | US | 9th Jan 1991 |
| 192.91.136.0/24 | 256 | ARIN | US | 11th Jan 1991 |
| 192.91.142.0/24 | 256 | ARIN | US | 15th Jan 1991 |
| 192.91.143.0/24 | 256 | ARIN | US | 15th Jan 1991 |
| 192.91.145.0/24 | 256 | ARIN | US | 16th Jan 1991 |
| 192.91.176.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.180.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.181.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.182.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.183.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.187.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.188.0/24 | 256 | ARIN | US | 17th Jan 1991 |
| 192.91.190.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.192.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.193.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.194.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.195.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.196.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.197.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.202.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.203.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.206.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.207.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.208.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.209.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.212.0/24 | 256 | ARIN | US | 18th Jan 1991 |
| 192.91.248.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.251.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.252.0/24 | 256 | ARIN | US | 21st Jan 1991 |
| 192.91.61.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.65.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.67.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.68.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.69.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.70.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.71.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.72.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.73.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.74.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.76.0/24 | 256 | ARIN | US | 4th Jan 1991 |
| 192.91.77.0/24 | 256 | ARIN | US | 4th Jan 1991 |