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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,302 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.175.179.0/24 | 256 | ARIN |  US | 2nd Jul 1993 |
| 198.175.180.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.175.181.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.175.182.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.175.183.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.175.185.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.175.187.0/24 | 256 | ARIN | US | 6th Jul 1993 |
| 198.175.188.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.189.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.190.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.191.0/24 | 256 | ARIN | US | 8th Mar 2013 |
| 198.175.193.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.201.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.204.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.175.207.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.208.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.209.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.210.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.211.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.216.0/23 | 512 | ARIN | US | 8th Jul 1993 |
| 198.175.218.0/23 | 512 | ARIN | US | 8th Jul 1993 |
| 198.175.220.0/23 | 512 | ARIN | US | 8th Jul 1993 |
| 198.175.222.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.223.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.224.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.175.225.0/24 | 256 | ARIN | US | 9th Jul 1993 |
| 198.175.226.0/24 | 256 | ARIN | US | 9th Jul 1993 |
| 198.175.227.0/24 | 256 | ARIN | US | 9th Jul 1993 |
| 198.175.231.0/24 | 256 | ARIN | US | 8th Mar 2013 |
| 198.175.232.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.233.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.234.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.235.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.237.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.238.0/23 | 512 | ARIN | US | 12th Jul 1993 |
| 198.175.240.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.175.241.0/24 | 256 | ARIN | US | 13th Jul 1993 |
| 198.175.243.0/24 | 256 | ARIN | US | 13th Jul 1993 |
| 198.175.244.0/22 | 1k | ARIN | US | 13th Jul 1993 |
| 198.175.28.0/22 | 1k | ARIN | US | 31st Mar 2021 |
| 198.175.32.0/21 | 2k | ARIN | US | 15th Jun 1993 |
| 198.175.4.0/22 | 1k | ARIN | US | 17th May 1993 |
| 198.175.40.0/22 | 1k | ARIN | US | 15th Jun 1993 |
| 198.175.46.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.175.47.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.175.48.0/23 | 512 | ARIN | US | 15th Jun 1993 |
| 198.175.58.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.175.59.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.175.60.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.175.61.0/24 | 256 | ARIN | US | 15th Jun 1993 |