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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.35.180.0/24 | 256 | ARIN |  US | 1st Jan 1991 |
| 192.35.181.0/24 | 256 | ARIN | US | 27th Mar 2020 |
| 192.35.182.0/24 | 256 | ARIN | US | 2nd May 1988 |
| 192.35.183.0/24 | 256 | RIPE NCC |  NL | 2nd May 1988 |
| 192.35.184.0/21 | 2k | RIPE NCC | NL | 2nd May 1988 |
| 192.35.192.0/24 | 256 | RIPE NCC | NL | 2nd May 1988 |
| 192.35.197.0/24 | 256 | RIPE NCC |  GB | 9th May 1988 |
| 192.35.207.0/24 | 256 | RIPE NCC |  IE | 27th May 1988 |
| 192.35.21.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.210.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.211.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.212.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.213.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.214.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.219.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.224.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.227.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.228.0/24 | 256 | ARIN | US | 1st Jun 1988 |
| 192.35.230.0/24 | 256 | ARIN | US | 17th May 1990 |
| 192.35.231.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.232.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.233.0/24 | 256 | ARIN | US | 26th Mar 1990 |
| 192.35.234.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.235.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.236.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.237.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.238.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.239.0/24 | 256 | ARIN | US | 16th May 1990 |
| 192.35.244.0/24 | 256 | RIPE NCC |  AT | 17th May 1990 |
| 192.35.245.0/24 | 256 | ARIN | US | 17th May 1990 |
| 192.35.247.0/24 | 256 | RIPE NCC |  SE | 17th May 1990 |
| 192.35.248.0/24 | 256 | APNIC |  AU | 17th May 1990 |
| 192.35.25.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.251.0/24 | 256 | ARIN | US | 21st May 1990 |
| 192.35.253.0/24 | 256 | ARIN | US | 21st May 1990 |
| 192.35.254.0/24 | 256 | ARIN | US | 21st May 1990 |
| 192.35.26.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.35.28.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.30.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.35.32.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.33.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.36.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.38.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.35.40.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.35.42.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.43.0/24 | 256 | ARIN | US | 16th Feb 1988 |
| 192.35.45.0/24 | 256 | ARIN | US | 23rd Feb 1988 |
| 192.35.47.0/24 | 256 | ARIN | US | 23rd Feb 1988 |
| 192.35.50.0/24 | 256 | ARIN | US | 26th Feb 1988 |
| 192.35.52.0/24 | 256 | ARIN | US | 18th Jul 1988 |