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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,392 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.166.8.0/24 | 256 | ARIN |  US | 20th Mar 1995 |
| 205.166.81.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.82.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.83.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.84.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.85.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.86.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.87.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.88.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.89.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.90.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.92.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.93.0/24 | 256 | ARIN | US | 28th Mar 1995 |
| 205.166.96.0/24 | 256 | ARIN | US | 29th Mar 1995 |
| 205.166.97.0/24 | 256 | ARIN | US | 29th Mar 1995 |
| 205.167.102.0/23 | 512 | ARIN | US | 31st May 1995 |
| 205.167.108.0/23 | 512 | ARIN | US | 8th Jun 1995 |
| 205.167.112.0/23 | 512 | ARIN | US | 13th Jun 1995 |
| 205.167.114.0/23 | 512 | ARIN | US | 13th Jun 1995 |
| 205.167.118.0/23 | 512 | ARIN | US | 29th Jun 1995 |
| 205.167.12.0/23 | 512 | ARIN | US | 23rd Mar 1995 |
| 205.167.122.0/23 | 512 | ARIN | US | 27th Jun 1995 |
| 205.167.124.0/23 | 512 | ARIN | US | 29th Jun 1995 |
| 205.167.14.0/23 | 512 | ARIN | US | 24th Mar 1995 |
| 205.167.150.0/23 | 512 | ARIN | US | 7th Aug 1995 |
| 205.167.152.0/23 | 512 | ARIN | US | 8th Aug 1995 |
| 205.167.154.0/23 | 512 | ARIN | US | 8th Aug 1995 |
| 205.167.16.0/23 | 512 | ARIN | US | 27th Mar 1995 |
| 205.167.160.0/23 | 512 | ARIN | US | 18th Aug 1995 |
| 205.167.170.0/23 | 512 | ARIN | US | 29th Aug 1995 |
| 205.167.172.0/23 | 512 | ARIN | US | 29th Aug 1995 |
| 205.167.174.0/23 | 512 | ARIN | US | 31st Aug 1995 |
| 205.167.178.0/23 | 512 | ARIN | US | 1st Sept 1995 |
| 205.167.190.0/23 | 512 | ARIN | US | 8th Sept 1995 |
| 205.167.192.0/23 | 512 | ARIN | US | 11th Sept 1995 |
| 205.167.194.0/23 | 512 | ARIN | US | 12th Sept 1995 |
| 205.167.196.0/23 | 512 | ARIN | US | 12th Sept 1995 |
| 205.167.200.0/23 | 512 | ARIN | US | 14th Sept 1995 |
| 205.167.204.0/23 | 512 | ARIN | US | 18th Sept 1995 |
| 205.167.206.0/23 | 512 | ARIN | US | 19th Sept 1995 |
| 205.167.208.0/23 | 512 | ARIN | US | 20th Sept 1995 |
| 205.167.214.0/24 | 256 | ARIN | US | 25th Sept 1995 |
| 205.167.216.0/23 | 512 | ARIN | US | 28th Sept 1995 |
| 205.167.218.0/23 | 512 | ARIN | US | 28th Sept 1995 |
| 205.167.224.0/23 | 512 | ARIN | US | 5th Oct 1995 |
| 205.167.228.0/23 | 512 | ARIN | US | 6th Oct 1995 |
| 205.167.230.0/23 | 512 | ARIN | US | 9th Oct 1995 |
| 205.167.234.0/23 | 512 | ARIN | US | 23rd Oct 1995 |
| 205.167.236.0/23 | 512 | ARIN | US | 25th Oct 1995 |
| 205.167.244.0/23 | 512 | ARIN | US | 27th Oct 1995 |