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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.164.170.0/23 | 512 | ARIN |  US | 15th Mar 1994 |
| 199.164.172.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.173.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.174.0/24 | 256 | ARIN | US | 3rd Oct 2025 |
| 199.164.175.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.178.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.179.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.180.0/23 | 512 | ARIN | US | 15th Mar 1994 |
| 199.164.182.0/24 | 256 | ARIN | US | 15th Mar 1994 |
| 199.164.183.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.184.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.185.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.187.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.188.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.189.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.190.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.193.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.194.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.195.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.196.0/23 | 512 | ARIN | US | 16th Mar 1994 |
| 199.164.198.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 199.164.199.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 199.164.200.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 199.164.201.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 199.164.202.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 199.164.210.0/24 | 256 | ARIN | US | 12th Dec 1994 |
| 199.164.211.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 199.164.213.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.214.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.215.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.216.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.218.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.219.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.221.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.222.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.223.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.224.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.225.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.226.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.228.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.229.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.230.0/23 | 512 | ARIN | US | 18th Mar 1994 |
| 199.164.232.0/23 | 512 | ARIN | US | 18th Mar 1994 |
| 199.164.234.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.235.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.236.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.237.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.238.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.239.0/24 | 256 | ARIN | US | 18th Mar 1994 |
| 199.164.240.0/24 | 256 | ARIN | US | 18th Mar 1994 |