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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,256 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.51.149.0/24 | 256 | ARIN |  US | 2nd Feb 1993 |
| 198.51.150.0/24 | 256 | ARIN | US | 2nd Feb 1993 |
| 198.51.151.0/24 | 256 | ARIN |  CA | 2nd Feb 1993 |
| 198.51.153.0/24 | 256 | ARIN | US | 2nd Feb 1993 |
| 198.51.154.0/24 | 256 | ARIN | US | 2nd Feb 1993 |
| 198.51.155.0/24 | 256 | ARIN | US | 2nd Feb 1993 |
| 198.51.157.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.159.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.160.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.161.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.162.0/24 | 256 | ARIN | US | 18th Sept 2013 |
| 198.51.163.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.164.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.165.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.166.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 198.51.174.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.175.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.176.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.177.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.178.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.180.0/22 | 1k | ARIN | US | 4th Feb 1993 |
| 198.51.184.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.185.0/24 | 256 | ARIN | US | 4th Feb 1993 |
| 198.51.187.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.188.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.189.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.190.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.191.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.193.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.196.0/24 | 256 | APNIC | US | 11th Feb 2011 |
| 198.51.198.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.199.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.200.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.201.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.202.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.203.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.204.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.205.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.206.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.207.0/24 | 256 | ARIN | US | 5th Feb 1993 |
| 198.51.211.0/24 | 256 | APNIC |  AU | 17th Feb 2011 |
| 198.51.216.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.217.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.218.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.219.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.220.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.221.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.224.0/24 | 256 | ARIN | US | 9th Feb 1993 |
| 198.51.23.0/24 | 256 | ARIN | US | 26th Jan 1993 |
| 198.51.234.0/23 | 512 | ARIN | US | 10th Feb 1993 |