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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.244.138.0/23 | 512 | ARIN |  US | 15th Aug 1994 |
| 199.244.145.0/24 | 256 | RIPE NCC |  GB | 16th Aug 1994 |
| 199.244.146.0/24 | 256 | ARIN | US | 17th Aug 1994 |
| 199.244.147.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.148.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.149.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.150.0/23 | 512 | ARIN | US | 19th Aug 1994 |
| 199.244.152.0/23 | 512 | ARIN | US | 19th Aug 1994 |
| 199.244.154.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.162.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.163.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.164.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.165.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.167.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.168.0/23 | 512 | ARIN | US | 19th Aug 1994 |
| 199.244.170.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.173.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.174.0/24 | 256 | ARIN | US | 19th Aug 1994 |
| 199.244.185.0/24 | 256 | ARIN | US | 6th Sept 1994 |
| 199.244.186.0/23 | 512 | ARIN | US | 6th Sept 1994 |
| 199.244.188.0/24 | 256 | ARIN | US | 6th Sept 1994 |
| 199.244.189.0/24 | 256 | ARIN | US | 6th Sept 1994 |
| 199.244.190.0/24 | 256 | ARIN | US | 6th Sept 1994 |
| 199.244.191.0/24 | 256 | ARIN | US | 6th Sept 1994 |
| 199.244.192.0/22 | 1k | ARIN | US | 6th Sept 1994 |
| 199.244.196.0/23 | 512 | ARIN | US | 6th Sept 1994 |
| 199.244.204.0/24 | 256 | ARIN | US | 23rd Apr 2012 |
| 199.244.205.0/24 | 256 | ARIN | US | 7th Sept 1994 |
| 199.244.206.0/23 | 512 | ARIN | US | 7th Sept 1994 |
| 199.244.208.0/24 | 256 | ARIN | US | 7th Sept 1994 |
| 199.244.209.0/24 | 256 | ARIN | US | 7th Sept 1994 |
| 199.244.210.0/23 | 512 | ARIN | US | 7th Sept 1994 |
| 199.244.213.0/24 | 256 | ARIN | US | 7th Sept 1994 |
| 199.244.214.0/23 | 512 | ARIN | US | 7th Sept 1994 |
| 199.244.216.0/22 | 1k | ARIN | US | 7th Sept 1994 |
| 199.244.222.0/24 | 256 | ARIN | US | 8th Sept 1994 |
| 199.244.224.0/24 | 256 | ARIN | US | 8th Sept 1994 |
| 199.244.225.0/24 | 256 | ARIN | US | 8th Sept 1994 |
| 199.244.226.0/23 | 512 | ARIN | US | 8th Sept 1994 |
| 199.244.228.0/23 | 512 | ARIN | US | 8th Sept 1994 |
| 199.244.230.0/24 | 256 | ARIN | US | 8th Sept 1994 |
| 199.244.231.0/24 | 256 | ARIN | US | 8th Sept 1994 |
| 199.244.232.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.234.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.236.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.237.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.238.0/23 | 512 | ARIN | US | 12th Sept 1994 |
| 199.244.241.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.242.0/24 | 256 | ARIN | US | 12th Sept 1994 |
| 199.244.243.0/24 | 256 | ARIN | US | 12th Sept 1994 |