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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.180.224.0/21 | 2k | ARIN |  US | 13th Jul 2011 |
| 199.180.32.0/20 | 4.1k | ARIN | US | 22nd Feb 1994 |
| 199.180.48.0/22 | 1k | ARIN | US | 22nd Feb 1994 |
| 199.181.0.0/21 | 2k | ARIN | US | 4th Mar 1994 |
| 199.181.100.0/22 | 1k | ARIN | US | 25th Jul 1994 |
| 199.181.104.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.105.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.106.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.109.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.110.0/23 | 512 | ARIN | US | 26th Jul 1994 |
| 199.181.112.0/23 | 512 | ARIN | US | 26th Jul 1994 |
| 199.181.114.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.115.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.116.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.117.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.118.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.119.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.120.0/24 | 256 | ARIN | US | 26th Jul 1994 |
| 199.181.121.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.181.124.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.181.125.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.181.126.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.181.128.0/24 | 256 | ARIN | US | 22nd Mar 1994 |
| 199.181.129.0/24 | 256 | ARIN | US | 28th Mar 1994 |
| 199.181.132.0/22 | 1k | ARIN | US | 28th Mar 1994 |
| 199.181.138.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.139.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.141.0/24 | 256 | ARIN | US | 14th Jul 1994 |
| 199.181.142.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.143.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.144.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.145.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.146.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.147.0/24 | 256 | ARIN | US | 29th Mar 1994 |
| 199.181.148.0/24 | 256 | ARIN | US | 11th Aug 2026 |
| 199.181.156.0/24 | 256 | ARIN | US | 30th Mar 1994 |
| 199.181.157.0/24 | 256 | ARIN | US | 30th Mar 1994 |
| 199.181.158.0/23 | 512 | ARIN | US | 30th Mar 1994 |
| 199.181.169.0/24 | 256 | ARIN | US | 30th Mar 1994 |
| 199.181.170.0/24 | 256 | ARIN | US | 30th Mar 1994 |
| 199.181.171.0/24 | 256 | ARIN | US | 30th Mar 1994 |
| 199.181.177.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.180.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.184.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.185.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.186.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.187.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.188.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.189.0/24 | 256 | ARIN | US | 31st Mar 1994 |
| 199.181.194.0/24 | 256 | ARIN | US | 31st Mar 1994 |