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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,458 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.19.140.0/24 | 256 | ARIN |  CA | 6th Oct 1994 |
| 204.19.15.0/24 | 256 | ARIN |  US | 9th Jun 2011 |
| 204.19.152.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.154.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.155.0/24 | 256 | ARIN | CA | 5th Sept 1995 |
| 204.19.156.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.157.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.158.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.159.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.16.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.160.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.161.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.163.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.164.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.166.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.17.0/24 | 256 | ARIN | CA | 6th Oct 1997 |
| 204.19.177.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.178.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.179.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.180.0/22 | 1k | ARIN | CA | 6th Oct 1994 |
| 204.19.184.0/23 | 512 | ARIN | CA | 22nd Dec 1995 |
| 204.19.187.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.204.0/23 | 512 | ARIN | US | 23rd Aug 2011 |
| 204.19.206.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.209.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.210.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.211.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.216.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.217.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.218.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.22.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.220.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.221.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.222.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.226.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.229.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.230.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.232.0/23 | 512 | ARIN | CA | 11th Dec 1994 |
| 204.19.234.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.236.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.24.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.240.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.242.0/24 | 256 | ARIN | US | 26th May 2011 |
| 204.19.243.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.245.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.246.0/23 | 512 | ARIN | CA | 6th Oct 1994 |
| 204.19.25.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.255.0/24 | 256 | ARIN | US | 27th May 2011 |
| 204.19.26.0/24 | 256 | ARIN | CA | 6th Oct 1994 |
| 204.19.27.0/24 | 256 | ARIN | CA | 6th Oct 1994 |