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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 198.175.62.0/23 | 512 | ARIN |  US | 15th Jun 1993 |
| 198.175.8.0/21 | 2k | ARIN | US | 10th May 1993 |
| 198.176.118.0/23 | 512 | ARIN | US | 27th Feb 1995 |
| 198.176.128.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.129.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.131.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.132.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.133.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.134.0/24 | 256 | ARIN | US | 14th Sept 1993 |
| 198.176.136.0/24 | 256 | ARIN | US | 15th Sept 1993 |
| 198.176.137.0/24 | 256 | ARIN | US | 15th Sept 1993 |
| 198.176.138.0/24 | 256 | ARIN | US | 15th Sept 1993 |
| 198.176.139.0/24 | 256 | ARIN | US | 15th Sept 1993 |
| 198.176.140.0/24 | 256 | ARIN | US | 15th Sept 1993 |
| 198.176.141.0/24 | 256 | ARIN | US | 16th Sept 1993 |
| 198.176.142.0/23 | 512 | ARIN | US | 16th Sept 1993 |
| 198.176.144.0/24 | 256 | ARIN | US | 16th Sept 1993 |
| 198.176.145.0/24 | 256 | ARIN | US | 17th Sept 1993 |
| 198.176.146.0/23 | 512 | ARIN | US | 17th Sept 1993 |
| 198.176.148.0/24 | 256 | ARIN | US | 17th Sept 1993 |
| 198.176.150.0/23 | 512 | ARIN | US | 17th Sept 1993 |
| 198.176.152.0/23 | 512 | ARIN | US | 17th Sept 1993 |
| 198.176.154.0/24 | 256 | ARIN | US | 12th Mar 2013 |
| 198.176.155.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.176.156.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.157.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.158.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.159.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.16.0/21 | 2k | ARIN | US | 10th May 1993 |
| 198.176.161.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.162.0/24 | 256 | ARIN | US | 20th Sept 1993 |
| 198.176.163.0/24 | 256 | ARIN | US | 17th Jan 1996 |
| 198.176.164.0/24 | 256 | ARIN | US | 21st Sept 1993 |
| 198.176.165.0/24 | 256 | ARIN | US | 21st Sept 1993 |
| 198.176.167.0/24 | 256 | ARIN | US | 21st Sept 1993 |
| 198.176.168.0/22 | 1k | ARIN | US | 21st Sept 1993 |
| 198.176.172.0/23 | 512 | ARIN | US | 21st Sept 1993 |
| 198.176.176.0/22 | 1k | ARIN | US | 22nd Sept 1993 |
| 198.176.180.0/24 | 256 | ARIN | US | 22nd Sept 1993 |
| 198.176.181.0/24 | 256 | ARIN | US | 22nd Sept 1993 |
| 198.176.193.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.176.198.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.176.199.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.176.200.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.176.201.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.176.202.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.176.203.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.176.205.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.176.206.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.176.208.0/22 | 1k | ARIN | US | 14th Oct 2014 |