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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,300 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 198.140.153.0/24 | 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 |
| 198.140.160.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.161.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.162.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.163.0/24 | 256 | ARIN | US | 30th Jun 1993 |
| 198.140.165.0/24 | 256 | ARIN | US | 2nd Jul 1993 |
| 198.140.166.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.140.167.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.168.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.169.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.171.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.172.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.173.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.174.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.175.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.176.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.177.0/24 | 256 | ARIN | US | 7th Jul 1993 |
| 198.140.185.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.140.186.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.140.187.0/24 | 256 | ARIN | US | 8th Jul 1993 |
| 198.140.188.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.140.192.0/23 | 512 | ARIN | US | 12th Jul 1993 |
| 198.140.194.0/24 | 256 | ARIN | US | 12th Jul 1993 |
| 198.140.197.0/24 | 256 | ARIN | US | 12th Jul 1993 |