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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 198.137.216.0/24 | 256 | ARIN |  US | 19th May 1993 |
| 198.137.217.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.218.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.219.0/24 | 256 | ARIN | US | 13th Jun 2013 |
| 198.137.220.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.221.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.222.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.223.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.228.0/24 | 256 | ARIN | US | 20th May 1993 |
| 198.137.230.0/24 | 256 | ARIN | US | 20th May 1993 |
| 198.137.231.0/24 | 256 | ARIN | US | 30th May 2025 |
| 198.137.236.0/24 | 256 | ARIN | US | 21st May 1993 |
| 198.137.237.0/24 | 256 | ARIN | US | 21st May 1993 |
| 198.137.242.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.137.243.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.137.244.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.137.245.0/24 | 256 | ARIN | US | 24th May 1993 |
| 198.137.246.0/23 | 512 | ARIN | US | 25th Apr 2013 |
| 198.137.248.0/24 | 256 | ARIN | US | 1st Jul 2022 |
| 198.137.249.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.137.250.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.137.251.0/24 | 256 | ARIN | US | 25th May 1993 |
| 198.137.255.0/24 | 256 | ARIN | US | 11th Oct 2018 |
| 198.137.32.0/19 | 8.2k | ARIN | US | 26th Apr 1993 |
| 198.14.128.0/18 | 16.4k | ARIN | US | 31st Dec 1992 |
| 198.140.112.0/23 | 512 | ARIN | US | 13th Sept 1993 |
| 198.140.120.0/21 | 2k | ARIN | US | 8th Oct 2012 |
| 198.140.129.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 198.140.130.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 198.140.131.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 198.140.132.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.133.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.136.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.137.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.138.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.139.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.142.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.143.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.140.144.0/24 | 256 | ARIN | US | 29th Jun 1993 |
| 198.140.145.0/24 | 256 | ARIN | US | 29th Jun 1993 |
| 198.140.146.0/24 | 256 | ARIN | US | 29th Jun 1993 |
| 198.140.147.0/24 | 256 | ARIN | US | 29th Jun 1993 |
| 198.140.148.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.149.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.150.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.151.0/24 | 256 | ARIN |  CA | 30th Jun 1993 |
| 198.140.153.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.157.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.159.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.16.0/21 | 2k | ARIN | US | 16th Apr 1993 |