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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
85,392 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.89.203.0/24 | 256 | ARIN |  US | 27th Mar 2025 |
| 204.89.204.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.205.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.206.0/24 | 256 | LACNIC |  MX | 17th Sept 1994 |
| 204.89.207.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.208.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.209.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.210.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.212.0/24 | 256 | ARIN | US | 17th Sept 1994 |
| 204.89.214.0/24 | 256 | ARIN | US | 24th Sept 2018 |
| 204.89.215.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.216.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.217.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.221.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.223.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.224.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 204.89.226.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.227.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.228.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.229.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.230.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.231.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.232.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.233.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.235.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.236.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.237.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 204.89.239.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.240.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.242.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.243.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.244.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.245.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.246.0/24 | 256 | ARIN | US | 8th Apr 2020 |
| 204.89.247.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 204.89.248.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.249.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 204.89.250.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.251.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.252.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.254.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.255.0/24 | 256 | ARIN | US | 28th Sept 1994 |
| 204.89.48.0/22 | 1k | ARIN | US | 22nd Aug 1994 |
| 204.89.52.0/22 | 1k | ARIN | US | 12th Oct 2017 |
| 204.9.0.0/22 | 1k | ARIN | US | 26th Aug 2004 |
| 204.9.160.0/21 | 2k | ARIN |  CA | 21st Oct 2004 |
| 204.9.168.0/22 | 1k | ARIN | US | 25th Oct 2004 |
| 204.9.176.0/22 | 1k | ARIN | US | 1st Nov 2005 |
| 204.9.186.0/24 | 256 | ARIN | US | 29th Jan 2018 |
| 204.9.187.0/24 | 256 | ARIN | US | 23rd Aug 2019 |