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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,248 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.151.232.0/24 | 256 | ARIN |  US | 25th Jun 1993 |
| 198.151.233.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.151.234.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.151.239.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.151.240.0/22 | 1k | ARIN | US | 25th Jun 1993 |
| 198.151.244.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.151.245.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.246.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.248.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.249.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.250.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.251.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 198.151.253.0/24 | 256 | ARIN | US | 29th Jun 1993 |
| 198.151.254.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.151.34.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.151.35.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.151.36.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.151.40.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.151.43.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.151.44.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.151.46.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.151.48.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.151.54.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.151.62.0/23 | 512 | ARIN | US | 4th May 1993 |
| 198.153.128.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.153.130.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.153.133.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.153.134.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.153.135.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.153.136.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.137.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.138.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.139.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.140.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.141.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.144.0/24 | 256 | ARIN | US | 6th Aug 1993 |
| 198.153.146.0/24 | 256 | ARIN | US | 9th Aug 1993 |
| 198.153.147.0/24 | 256 | ARIN | US | 9th Aug 1993 |
| 198.153.149.0/24 | 256 | ARIN | US | 9th Aug 1993 |
| 198.153.150.0/24 | 256 | ARIN | US | 10th Aug 1993 |
| 198.153.151.0/24 | 256 | ARIN | US | 10th Aug 1993 |
| 198.153.164.0/24 | 256 | ARIN | US | 10th Aug 1993 |
| 198.153.165.0/24 | 256 | ARIN | US | 11th Aug 1993 |
| 198.153.166.0/23 | 512 | ARIN | US | 11th Aug 1993 |
| 198.153.168.0/24 | 256 | ARIN | US | 11th Aug 1993 |
| 198.153.170.0/24 | 256 | ARIN | US | 11th Aug 1993 |
| 198.153.171.0/24 | 256 | ARIN | US | 11th Aug 1993 |
| 198.153.172.0/22 | 1k | ARIN | US | 11th Aug 1993 |
| 198.153.176.0/21 | 2k | ARIN | US | 11th Aug 1993 |
| 198.153.190.0/23 | 512 | ARIN | US | 11th Aug 1993 |