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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.103.111.0/24 | 256 | ARIN |  US | 26th Jun 1994 |
| 199.103.112.0/24 | 256 | ARIN | US | 26th Jun 1994 |
| 199.103.113.0/24 | 256 | ARIN | US | 26th Jun 1994 |
| 199.103.114.0/23 | 512 | ARIN | US | 26th Jun 1994 |
| 199.103.116.0/23 | 512 | ARIN | US | 26th Jun 1994 |
| 199.103.119.0/24 | 256 | ARIN |  IT | 26th Jun 1994 |
| 199.103.12.0/24 | 256 | RIPE NCC |  NL | 11th Jan 1994 |
| 199.103.120.0/23 | 512 | ARIN | US | 26th Jun 1994 |
| 199.103.123.0/24 | 256 | ARIN |  BE | 26th Jun 1994 |
| 199.103.124.0/22 | 1k | ARIN | BE | 26th Jun 1994 |
| 199.103.13.0/24 | 256 | ARIN | US | 11th Jan 1994 |
| 199.103.14.0/23 | 512 | ARIN | US | 11th Jan 1994 |
| 199.103.22.0/23 | 512 | ARIN | US | 23rd Aug 2019 |
| 199.103.64.0/22 | 1k | ARIN |  GB | 21st Jun 1994 |
| 199.103.68.0/24 | 256 | ARIN |  SG | 25th Jun 1994 |
| 199.103.69.0/24 | 256 | ARIN | US | 25th Jun 1994 |
| 199.103.70.0/23 | 512 | ARIN | US | 25th Jun 1994 |
| 199.103.72.0/24 | 256 | ARIN | US | 25th Jun 1994 |
| 199.103.73.0/24 | 256 | ARIN |  ES | 25th Jun 1994 |
| 199.103.74.0/24 | 256 | ARIN |  LU | 25th Jun 1994 |
| 199.103.75.0/24 | 256 | ARIN |  DE | 25th Jun 1994 |
| 199.103.76.0/23 | 512 | ARIN | DE | 25th Jun 1994 |
| 199.103.78.0/23 | 512 | ARIN | US | 25th Jun 1994 |
| 199.103.80.0/24 | 256 | ARIN | US | 25th Jun 1994 |
| 199.103.81.0/24 | 256 | ARIN | ES | 25th Jun 1994 |
| 199.103.84.0/24 | 256 | ARIN | US | 25th Jun 1994 |
| 199.103.86.0/24 | 256 | ARIN | GB | 25th Jun 1994 |
| 199.103.87.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 199.103.88.0/24 | 256 | ARIN |  FR | 25th Jun 1994 |
| 199.103.89.0/24 | 256 | ARIN | US | 19th Jul 2019 |
| 199.103.92.0/24 | 256 | ARIN | FR | 25th Jun 1994 |
| 199.103.93.0/24 | 256 | ARIN | DE | 25th Jun 1994 |
| 199.103.94.0/23 | 512 | ARIN | US | 25th Jun 1994 |
| 199.103.97.0/24 | 256 | ARIN | DE | 25th Jun 1994 |
| 199.103.98.0/23 | 512 | ARIN | DE | 25th Jun 1994 |
| 199.104.10.0/24 | 256 | ARIN | US | 24th Jul 2025 |
| 199.104.106.0/23 | 512 | ARIN | US | 10th Jan 1994 |
| 199.104.108.0/22 | 1k | ARIN | US | 10th Jan 1994 |
| 199.104.12.0/23 | 512 | ARIN | US | 10th Jan 1994 |
| 199.104.16.0/22 | 1k | ARIN | US | 10th Jan 1994 |
| 199.104.20.0/24 | 256 | ARIN | US | 6th Feb 2026 |
| 199.104.32.0/19 | 8.2k | ARIN | US | 10th Jan 1994 |
| 199.104.68.0/23 | 512 | ARIN | US | 10th Jan 1994 |
| 199.104.71.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.104.72.0/22 | 1k | ARIN | US | 10th Jan 1994 |
| 199.104.78.0/23 | 512 | ARIN | US | 10th Jan 1994 |
| 199.104.8.0/24 | 256 | ARIN | US | 24th Jul 2025 |
| 199.104.88.0/23 | 512 | ARIN | US | 10th Jan 1994 |
| 199.104.90.0/24 | 256 | ARIN | US | 10th Jan 1994 |
| 199.104.94.0/24 | 256 | ARIN | US | 10th Jan 1994 |