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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,356 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 206.197.171.0/24 | 256 | ARIN |  US | 10th Aug 1995 |
| 206.197.172.0/24 | 256 | ARIN | US | 10th Aug 1995 |
| 206.197.173.0/24 | 256 | ARIN | US | 10th Aug 1995 |
| 206.197.174.0/24 | 256 | ARIN | US | 10th Aug 1995 |
| 206.197.178.0/24 | 256 | ARIN | US | 10th Aug 1995 |
| 206.197.179.0/24 | 256 | ARIN | US | 14th Aug 1995 |
| 206.197.18.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.180.0/24 | 256 | ARIN | US | 14th Aug 1995 |
| 206.197.183.0/24 | 256 | ARIN | US | 14th Aug 1995 |
| 206.197.185.0/24 | 256 | ARIN | US | 14th Aug 1995 |
| 206.197.186.0/24 | 256 | ARIN |  CA | 2nd Jul 2026 |
| 206.197.188.0/24 | 256 | ARIN | US | 22nd Aug 1995 |
| 206.197.19.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.190.0/24 | 256 | ARIN | US | 22nd Aug 1995 |
| 206.197.191.0/24 | 256 | ARIN | US | 22nd Aug 1995 |
| 206.197.192.0/24 | 256 | ARIN | US | 23rd Aug 1995 |
| 206.197.193.0/24 | 256 | ARIN | US | 23rd Aug 1995 |
| 206.197.194.0/24 | 256 | ARIN | US | 23rd Aug 1995 |
| 206.197.195.0/24 | 256 | ARIN | US | 23rd Aug 1995 |
| 206.197.196.0/24 | 256 | ARIN | US | 23rd Aug 1995 |
| 206.197.2.0/24 | 256 | ARIN | US | 14th Jun 1995 |
| 206.197.20.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.203.0/24 | 256 | ARIN | US | 25th Aug 1995 |
| 206.197.204.0/24 | 256 | ARIN | US | 28th Aug 1995 |
| 206.197.205.0/24 | 256 | ARIN | US | 29th Aug 1995 |
| 206.197.208.0/24 | 256 | ARIN |  GB | 10th Feb 2011 |
| 206.197.21.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.213.0/24 | 256 | ARIN | US | 30th Aug 1995 |
| 206.197.214.0/24 | 256 | ARIN | US | 30th Aug 1995 |
| 206.197.215.0/24 | 256 | ARIN | US | 30th Aug 1995 |
| 206.197.216.0/24 | 256 | ARIN | US | 31st Aug 1995 |
| 206.197.218.0/24 | 256 | ARIN | US | 31st Aug 1995 |
| 206.197.22.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.220.0/24 | 256 | ARIN | US | 31st Aug 1995 |
| 206.197.221.0/24 | 256 | ARIN | US | 31st Aug 1995 |
| 206.197.223.0/24 | 256 | ARIN | CA | 2nd Jul 2026 |
| 206.197.225.0/24 | 256 | ARIN | US | 2nd Nov 1995 |
| 206.197.226.0/24 | 256 | ARIN | US | 5th Sept 1995 |
| 206.197.227.0/24 | 256 | ARIN | US | 5th Sept 1995 |
| 206.197.228.0/24 | 256 | ARIN | US | 5th Sept 1995 |
| 206.197.229.0/24 | 256 | ARIN | US | 5th Sept 1995 |
| 206.197.23.0/24 | 256 | ARIN | US | 19th Jun 1995 |
| 206.197.230.0/24 | 256 | ARIN | US | 8th Sept 1995 |
| 206.197.232.0/24 | 256 | ARIN | US | 15th Sept 1995 |
| 206.197.233.0/24 | 256 | ARIN | US | 15th Sept 1995 |
| 206.197.234.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.235.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.237.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.239.0/24 | 256 | ARIN | US | 19th Sept 1995 |
| 206.197.24.0/24 | 256 | ARIN | US | 19th Jun 1995 |