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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.147.247.0/24 | 256 | RIPE NCC |  IT | 25th Feb 1992 |
| 192.147.251.0/24 | 256 | RIPE NCC |  DE | 25th Feb 1992 |
| 192.147.252.0/24 | 256 | ARIN |  US | 25th Feb 1992 |
| 192.147.254.0/24 | 256 | ARIN | US | 25th Feb 1992 |
| 192.147.27.0/24 | 256 | ARIN | US | 10th Feb 1992 |
| 192.147.28.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 192.147.29.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.3.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.30.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.32.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.33.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.35.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.36.0/24 | 256 | RIPE NCC |  GB | 12th Feb 1992 |
| 192.147.38.0/24 | 256 | ARIN | US | 2nd Mar 1992 |
| 192.147.39.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.4.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.42.0/24 | 256 | RIPE NCC |  PL | 12th Feb 1992 |
| 192.147.45.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.46.0/24 | 256 | ARIN | US | 12th Feb 1992 |
| 192.147.47.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.48.0/23 | 512 | ARIN | US | 12th May 1992 |
| 192.147.5.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.50.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.51.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.52.0/23 | 512 | ARIN | US | 12th May 1992 |
| 192.147.6.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.64.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.65.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.67.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.7.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.72.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.74.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.75.0/24 | 256 | ARIN | US | 19th Feb 1992 |
| 192.147.76.0/24 | 256 | RIPE NCC |  PT | 14th Feb 1992 |
| 192.147.77.0/24 | 256 | RIPE NCC | PT | 14th Feb 1992 |
| 192.147.78.0/24 | 256 | RIPE NCC | PT | 14th Feb 1992 |
| 192.147.79.0/24 | 256 | RIPE NCC |  FR | 14th Feb 1992 |
| 192.147.8.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.82.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.83.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.84.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.85.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.86.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.87.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.9.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.90.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.92.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.93.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.94.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.95.0/24 | 256 | ARIN | US | 14th Feb 1992 |