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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,244 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.148.137.0/24 | 256 | ARIN |  US | 19th Jul 1993 |
| 198.148.138.0/23 | 512 | ARIN | US | 19th Jul 1993 |
| 198.148.14.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.148.140.0/23 | 512 | ARIN | US | 19th Jul 1993 |
| 198.148.142.0/24 | 256 | ARIN | US | 19th Jul 1993 |
| 198.148.143.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.144.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.145.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.146.0/24 | 256 | ARIN | US | 6th Apr 2026 |
| 198.148.148.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.15.0/24 | 256 | ARIN | US | 30th Jan 2014 |
| 198.148.151.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.154.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.156.0/24 | 256 | ARIN | US | 21st Jul 1993 |
| 198.148.157.0/24 | 256 | ARIN | US | 22nd Jul 1993 |
| 198.148.158.0/24 | 256 | ARIN | US | 22nd Jul 1993 |
| 198.148.164.0/24 | 256 | ARIN | US | 22nd Jul 1993 |
| 198.148.167.0/24 | 256 | ARIN | US | 22nd Jul 1993 |
| 198.148.168.0/24 | 256 | ARIN | US | 23rd Jul 1993 |
| 198.148.172.0/24 | 256 | ARIN | US | 28th Jul 1993 |
| 198.148.175.0/24 | 256 | ARIN | US | 28th Jul 1993 |
| 198.148.176.0/24 | 256 | ARIN | US | 28th Jul 1993 |
| 198.148.177.0/24 | 256 | RIPE NCC |  CH | 1st Sept 1993 |
| 198.148.178.0/24 | 256 | RIPE NCC | CH | 1st Sept 1993 |
| 198.148.179.0/24 | 256 | ARIN | US | 28th Jul 1993 |
| 198.148.187.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 198.148.188.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 198.148.189.0/24 | 256 | APNIC |  AU | 2nd Aug 1993 |
| 198.148.196.0/23 | 512 | APNIC | AU | 2nd Aug 1993 |
| 198.148.198.0/24 | 256 | ARIN | US | 2nd Aug 1993 |
| 198.148.199.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.200.0/23 | 512 | ARIN | US | 3rd Aug 1993 |
| 198.148.202.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.208.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.211.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.212.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.213.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.214.0/23 | 512 | ARIN | US | 3rd Aug 1993 |
| 198.148.218.0/23 | 512 | ARIN | US | 3rd Aug 1993 |
| 198.148.220.0/23 | 512 | ARIN | US | 3rd Aug 1993 |
| 198.148.222.0/24 | 256 | ARIN | US | 3rd Aug 1993 |
| 198.148.223.0/24 | 256 | ARIN | US | 4th Aug 1993 |
| 198.148.224.0/23 | 512 | ARIN | US | 4th Aug 1993 |
| 198.148.226.0/24 | 256 | ARIN | US | 4th Aug 1993 |
| 198.148.227.0/24 | 256 | ARIN | US | 4th Aug 1993 |
| 198.148.228.0/24 | 256 | ARIN | US | 4th Aug 1993 |
| 198.148.229.0/24 | 256 | ARIN | US | 4th Aug 1993 |
| 198.148.240.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.241.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.242.0/24 | 256 | ARIN | US | 5th Aug 1993 |