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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,244 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.135.139.0/24 | 256 | ARIN |  US | 18th May 1993 |
| 198.135.141.0/24 | 256 | ARIN | US | 18th May 1993 |
| 198.135.153.0/24 | 256 | ARIN | US | 26th Dec 2024 |
| 198.135.16.0/21 | 2k | ARIN | US | 7th Apr 1993 |
| 198.135.167.0/24 | 256 | RIPE NCC |  GB | 18th May 1993 |
| 198.135.179.0/24 | 256 | ARIN | US | 20th Dec 2024 |
| 198.135.186.0/23 | 512 | ARIN | US | 15th Jul 2020 |
| 198.135.194.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.195.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.197.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.198.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.200.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.206.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.207.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.208.0/22 | 1k | ARIN | US | 19th May 1993 |
| 198.135.212.0/23 | 512 | ARIN | US | 19th May 1993 |
| 198.135.214.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.135.215.0/24 | 256 | ARIN | US | 20th May 1993 |
| 198.135.217.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.135.218.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.135.219.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.135.223.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.225.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.227.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.228.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.231.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.232.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.234.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.237.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.238.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.239.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.24.0/22 | 1k | ARIN | US | 7th Apr 1993 |
| 198.135.240.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.241.0/24 | 256 | ARIN | US | 3rd Oct 2025 |
| 198.135.242.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.135.243.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.244.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.246.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.247.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.248.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.251.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.253.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.254.0/24 | 256 | ARIN | US | 26th May 1993 |
| 198.135.255.0/24 | 256 | ARIN | US | 4th Jun 2013 |
| 198.135.64.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.65.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.66.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.67.0/24 | 256 | ARIN | US | 30th Sept 1996 |
| 198.135.68.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.135.69.0/24 | 256 | ARIN | US | 10th May 1993 |