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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.120.136.0/23 | 512 | ARIN |  US | 1st Mar 1994 |
| 199.120.138.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.120.139.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.120.140.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.145.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.146.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.155.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.156.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.159.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.160.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.161.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.162.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.163.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.164.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.165.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.168.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.169.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.170.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.175.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.176.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.178.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.179.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.180.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.182.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.183.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.184.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.185.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.186.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.187.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.188.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 199.120.190.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.192.0/23 | 512 | ARIN | US | 4th Mar 1994 |
| 199.120.194.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.195.0/24 | 256 | ARIN | US | 6th May 2021 |
| 199.120.196.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.197.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.198.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.199.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.200.0/23 | 512 | ARIN | US | 4th Mar 1994 |
| 199.120.202.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.204.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 199.120.206.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 199.120.208.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 199.120.209.0/24 | 256 | ARIN | US | 12th Sept 2012 |
| 199.120.211.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 199.120.212.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 199.120.213.0/24 | 256 | ARIN | US | 7th Aug 2026 |
| 199.120.214.0/23 | 512 | ARIN | US | 8th Mar 1994 |
| 199.120.216.0/22 | 1k | ARIN | US | 4th Mar 1994 |
| 199.120.220.0/23 | 512 | ARIN | US | 4th Mar 1994 |