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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,458 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.225.230.0/24 | 256 | ARIN |  CA | 10th Jan 1995 |
| 204.225.231.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.233.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.234.0/23 | 512 | ARIN | CA | 10th Jan 1995 |
| 204.225.236.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.237.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.238.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.239.0/24 | 256 | ARIN |  US | 10th Jan 1994 |
| 204.225.240.0/21 | 2k | ARIN | CA | 10th Jan 1994 |
| 204.225.250.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.251.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.252.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.253.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.254.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.255.0/24 | 256 | ARIN | CA | 28th Oct 2010 |
| 204.225.32.0/22 | 1k | ARIN | CA | 10th Jan 1995 |
| 204.225.36.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.37.0/24 | 256 | ARIN | CA | 14th Apr 2015 |
| 204.225.38.0/23 | 512 | ARIN | US | 27th Sept 2010 |
| 204.225.46.0/23 | 512 | ARIN | CA | 10th Jan 1995 |
| 204.225.48.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.49.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.50.0/23 | 512 | ARIN | CA | 10th Jan 1995 |
| 204.225.52.0/23 | 512 | ARIN | US | 10th Jan 1995 |
| 204.225.54.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.55.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.56.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.57.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.6.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.84.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.85.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.98.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.225.99.0/24 | 256 | ARIN | CA | 10th Jan 1995 |
| 204.226.0.0/16 | 65.5k | ARIN | CA | 12th Jan 1995 |
| 204.227.160.0/19 | 8.2k | ARIN | US | 23rd Jan 1995 |
| 204.227.32.0/19 | 8.2k | ARIN | US | 12th Jan 1995 |
| 204.227.64.0/19 | 8.2k | ARIN | US | 17th Jan 1995 |
| 204.227.96.0/19 | 8.2k | ARIN | US | 20th Jan 1995 |
| 204.228.160.0/21 | 2k | ARIN | US | 12th Jan 1995 |
| 204.228.168.0/23 | 512 | ARIN | US | 12th Jan 1995 |
| 204.228.170.0/24 | 256 | ARIN | US | 12th Jan 1995 |
| 204.228.171.0/24 | 256 | ARIN | US | 12th Jan 1995 |
| 204.228.172.0/23 | 512 | ARIN | US | 12th Jan 1995 |
| 204.228.174.0/24 | 256 | ARIN | US | 12th Jan 1995 |
| 204.229.0.0/19 | 8.2k | ARIN | US | 12th Jan 1995 |
| 204.229.128.0/18 | 16.4k | ARIN | US | 12th Jan 1995 |
| 204.229.32.0/19 | 8.2k | ARIN | US | 12th Jan 1995 |
| 204.229.64.0/19 | 8.2k | ARIN | US | 12th Jan 1995 |
| 204.229.96.0/19 | 8.2k | ARIN | US | 12th Jan 1995 |
| 204.230.0.0/16 | 65.5k | ARIN | US | 12th Jan 1995 |