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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,201 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.31.45.0/24 | 256 | ARIN |  US | 13th Mar 1991 |
| 192.31.48.0/24 | 256 | ARIN | US | 8th Feb 1995 |
| 192.31.5.0/24 | 256 | ARIN | US | 12th Mar 1987 |
| 192.31.52.0/22 | 1k | ARIN |  CA | 15th Nov 2012 |
| 192.31.6.0/24 | 256 | ARIN | CA | 13th Mar 1987 |
| 192.31.62.0/24 | 256 | RIPE NCC |  GB | 6th May 1987 |
| 192.31.63.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.64.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.65.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.66.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.67.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.68.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.69.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.7.0/24 | 256 | ARIN | US | 29th Jun 1987 |
| 192.31.70.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.71.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.72.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.73.0/24 | 256 | ARIN | US | 8th May 1987 |
| 192.31.77.0/24 | 256 | ARIN | US | 10th May 1987 |
| 192.31.78.0/24 | 256 | ARIN | US | 10th May 1987 |
| 192.31.79.0/24 | 256 | ARIN | US | 14th May 1987 |
| 192.31.81.0/24 | 256 | ARIN | US | 18th May 1988 |
| 192.31.84.0/24 | 256 | ARIN | US | 22nd May 1987 |
| 192.31.85.0/24 | 256 | ARIN | US | 2nd Jun 1997 |
| 192.31.86.0/24 | 256 | ARIN | US | 2nd Jun 1997 |
| 192.31.90.0/24 | 256 | ARIN | US | 5th Jun 1987 |
| 192.31.92.0/24 | 256 | ARIN | US | 13th Mar 1991 |
| 192.31.97.0/24 | 256 | ARIN | US | 10th Jun 1987 |
| 192.31.99.0/24 | 256 | ARIN | US | 11th Jul 1988 |
| 192.32.0.0/16 | 65.5k | ARIN | US | 2nd Aug 2011 |
| 192.33.11.0/24 | 256 | ARIN | US | 6th May 2014 |
| 192.33.113.0/24 | 256 | RIPE NCC |  FR | 10th Nov 1987 |
| 192.33.114.0/24 | 256 | RIPE NCC | FR | 10th Nov 1987 |
| 192.33.129.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.33.130.0/24 | 256 | RIPE NCC | GB | 2nd Dec 1987 |
| 192.33.131.0/24 | 256 | RIPE NCC |  NL | 2nd Dec 1987 |
| 192.33.137.0/24 | 256 | ARIN | US | 7th Apr 1993 |
| 192.33.138.0/24 | 256 | ARIN | US | 7th Apr 1993 |
| 192.33.142.0/24 | 256 | ARIN | US | 8th Dec 1987 |
| 192.33.143.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.144.0/24 | 256 | RIPE NCC | FR | 24th Aug 2009 |
| 192.33.145.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.148.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.149.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.15.0/24 | 256 | RIPE NCC | FR | 27th Oct 1987 |
| 192.33.150.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.151.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.152.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.154.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |
| 192.33.155.0/24 | 256 | RIPE NCC | FR | 15th Dec 1987 |