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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.135.235.0/24 | 256 | ARIN |  US | 30th Dec 1991 |
| 192.135.236.0/24 | 256 | ARIN | US | 30th Dec 1991 |
| 192.135.239.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.240.0/23 | 512 | ARIN | US | 2nd Jan 1992 |
| 192.135.242.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.243.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.244.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.245.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.246.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.247.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.249.0/24 | 256 | ARIN | US | 2nd Jan 1992 |
| 192.135.255.0/24 | 256 | ARIN | US | 27th May 2015 |
| 192.135.3.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.135.38.0/24 | 256 | ARIN | US | 21st Nov 1991 |
| 192.135.39.0/24 | 256 | ARIN | US | 30th Apr 2015 |
| 192.135.40.0/24 | 256 | ARIN |  CA | 21st Nov 1991 |
| 192.135.41.0/24 | 256 | ARIN | CA | 21st Nov 1991 |
| 192.135.42.0/24 | 256 | ARIN | CA | 21st Nov 1991 |
| 192.135.43.0/24 | 256 | ARIN | CA | 21st Nov 1991 |
| 192.135.44.0/24 | 256 | ARIN | US | 21st Nov 1991 |
| 192.135.45.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.135.46.0/24 | 256 | RIPE NCC |  NO | 21st Nov 1991 |
| 192.135.47.0/24 | 256 | ARIN | US | 21st Nov 1991 |
| 192.135.48.0/24 | 256 | ARIN | CA | 21st Nov 1991 |
| 192.135.49.0/24 | 256 | ARIN | US | 21st Nov 1991 |
| 192.135.51.0/24 | 256 | RIPE NCC |  DE | 29th Mar 1992 |
| 192.135.52.0/24 | 256 | RIPE NCC |  GB | 22nd Nov 1991 |
| 192.135.53.0/24 | 256 | RIPE NCC | GB | 22nd Nov 1991 |
| 192.135.54.0/23 | 512 | ARIN | US | 28th Jan 2015 |
| 192.135.6.0/24 | 256 | ARIN | US | 29th Mar 1992 |
| 192.135.65.0/24 | 256 | ARIN | US | 26th Nov 1991 |
| 192.135.66.0/24 | 256 | RIPE NCC | GB | 26th Nov 1991 |
| 192.135.67.0/24 | 256 | ARIN | US | 26th Nov 1991 |
| 192.135.68.0/24 | 256 | RIPE NCC | GB | 26th Nov 1991 |
| 192.135.69.0/24 | 256 | ARIN | US | 27th Nov 1991 |
| 192.135.70.0/24 | 256 | ARIN | US | 27th Nov 1991 |
| 192.135.71.0/24 | 256 | ARIN | US | 20th May 1992 |
| 192.135.72.0/22 | 1k | ARIN | US | 20th May 1992 |
| 192.135.77.0/24 | 256 | ARIN | CA | 5th May 1992 |
| 192.135.78.0/24 | 256 | ARIN | US | 3rd Dec 1991 |
| 192.135.81.0/24 | 256 | ARIN | US | 3rd Dec 1991 |
| 192.135.82.0/24 | 256 | RIPE NCC |  SE | 3rd Dec 1991 |
| 192.135.83.0/24 | 256 | ARIN | CA | 18th Dec 1991 |
| 192.135.85.0/24 | 256 | ARIN | US | 5th Dec 1991 |
| 192.135.87.0/24 | 256 | ARIN | US | 5th Dec 1991 |
| 192.135.88.0/24 | 256 | ARIN | US | 5th Dec 1991 |
| 192.135.90.0/23 | 512 | APNIC |  PK | 26th Sept 2017 |
| 192.135.93.0/24 | 256 | ARIN | US | 28th Apr 2015 |
| 192.135.94.0/24 | 256 | APNIC |  JP | 28th Apr 1993 |
| 192.135.96.0/24 | 256 | APNIC | JP | 5th May 1992 |