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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,493 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.107.196.0/24 | 256 | ARIN |  US | 28th Oct 1994 |
| 204.107.197.0/24 | 256 | ARIN | US | 28th Oct 1994 |
| 204.107.198.0/24 | 256 | ARIN | US | 31st Oct 1994 |
| 204.107.199.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.201.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.202.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.203.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.205.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.206.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.207.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.208.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.210.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 204.107.211.0/24 | 256 | ARIN | US | 8th Jun 1995 |
| 204.107.212.0/24 | 256 | ARIN | US | 1st Nov 1994 |
| 204.107.213.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.214.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.215.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.217.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.219.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.220.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.222.0/24 | 256 | ARIN | US | 3rd Nov 1994 |
| 204.107.224.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.225.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.226.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 204.107.227.0/24 | 256 | ARIN | US | 11th Jul 1994 |
| 204.107.228.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.229.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.230.0/24 | 256 | ARIN | US | 1st Jul 2025 |
| 204.107.231.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.233.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.234.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.236.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.237.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.238.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.239.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.24.0/23 | 512 | ARIN | US | 25th Jul 1994 |
| 204.107.240.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.241.0/24 | 256 | ARIN | US | 7th Nov 1994 |
| 204.107.243.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 204.107.244.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 204.107.245.0/24 | 256 | ARIN | US | 8th Nov 1994 |
| 204.107.247.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.249.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.251.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.253.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.254.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.255.0/24 | 256 | ARIN | US | 9th Nov 1994 |
| 204.107.32.0/21 | 2k | ARIN | US | 29th Aug 1994 |
| 204.107.40.0/22 | 1k | ARIN | US | 29th Aug 1994 |
| 204.107.44.0/22 | 1k | ARIN | US | 29th Aug 1994 |