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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
27,021 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 204.9.168.0/22 | 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 |
| 204.9.190.0/23 | 512 | ARIN | US | 7th Oct 2019 |
| 204.9.192.0/21 | 2k | ARIN | US | 26th Oct 2004 |
| 204.9.68.0/22 | 1k | ARIN | US | 21st Sept 2004 |
| 204.9.90.0/23 | 512 | ARIN | US | 10th May 2019 |
| 204.90.10.0/23 | 512 | ARIN | US | 8th Dec 2011 |
| 204.90.100.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.104.0/24 | 256 | ARIN | US | 18th Apr 1995 |
| 204.90.105.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.107.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 204.90.108.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.109.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.110.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.111.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 204.90.112.0/24 | 256 | ARIN | US | 9th Feb 1995 |