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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 198.153.56.0/23 | 512 | ARIN |  US | 3rd May 1993 |
| 198.153.58.0/23 | 512 | ARIN | US | 1st Jul 2025 |
| 198.154.0.0/23 | 512 | ARIN | US | 3rd May 1993 |
| 198.156.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.157.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.158.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.16.0.0/22 | 1k | ARIN | US | 30th Nov 1992 |
| 198.16.8.0/21 | 2k | ARIN | US | 3rd Dec 1992 |
| 198.160.132.0/23 | 512 | ARIN | US | 20th Aug 1993 |
| 198.160.137.0/24 | 256 | ARIN | US | 23rd Aug 1993 |
| 198.160.138.0/24 | 256 | ARIN | US | 23rd Aug 1993 |
| 198.160.141.0/24 | 256 | ARIN | US | 24th Aug 1993 |
| 198.160.142.0/24 | 256 | ARIN | US | 24th Aug 1993 |
| 198.160.144.0/24 | 256 | ARIN | US | 24th Aug 1993 |
| 198.160.145.0/24 | 256 | ARIN | US | 24th Aug 1993 |
| 198.160.146.0/24 | 256 | ARIN | US | 24th Aug 1993 |
| 198.160.153.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.154.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.156.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.158.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.159.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.16.0/21 | 2k | ARIN | US | 4th May 1993 |
| 198.160.160.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.162.0/24 | 256 | ARIN | US | 26th Aug 1993 |
| 198.160.163.0/24 | 256 | ARIN | US | 30th Aug 1993 |
| 198.160.170.0/24 | 256 | ARIN | US | 30th Aug 1993 |
| 198.160.172.0/24 | 256 | ARIN | US | 30th Aug 1993 |
| 198.160.174.0/24 | 256 | ARIN | US | 30th Aug 1993 |
| 198.160.177.0/24 | 256 | ARIN | US | 31st Aug 1993 |
| 198.160.180.0/24 | 256 | ARIN | US | 31st Aug 1993 |
| 198.160.186.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.187.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.188.0/23 | 512 | ARIN | US | 3rd Sept 1993 |
| 198.160.194.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.195.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.196.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.198.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.199.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.201.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.202.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.203.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.204.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.205.0/24 | 256 | ARIN | US | 3rd Sept 1993 |
| 198.160.206.0/24 | 256 | ARIN | US | 7th Sept 1993 |
| 198.160.207.0/24 | 256 | ARIN | US | 1st Nov 2013 |
| 198.160.210.0/24 | 256 | ARIN | US | 7th Sept 1993 |
| 198.160.212.0/22 | 1k | ARIN | US | 8th Sept 1993 |
| 198.160.216.0/24 | 256 | ARIN | US | 8th Sept 1993 |
| 198.160.218.0/24 | 256 | ARIN | US | 8th Sept 1993 |
| 198.160.219.0/24 | 256 | ARIN | US | 9th Sept 1993 |