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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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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 |
|---|---|---|---|---|
| 198.134.139.0/24 | 256 | ARIN |  US | 4th May 1993 |
| 198.134.140.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.134.141.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.134.143.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.134.147.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.134.148.0/24 | 256 | ARIN | US | 4th May 1993 |
| 198.134.149.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.134.150.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.134.160.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.134.255.0/24 | 256 | ARIN | US | 17th Jan 2014 |
| 198.134.4.0/24 | 256 | ARIN | US | 1st Apr 1993 |
| 198.134.5.0/24 | 256 | ARIN | US | 16th Jan 2014 |
| 198.135.110.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.111.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.112.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.113.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.114.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.115.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.120.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.122.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.123.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.127.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.135.128.0/24 | 256 | ARIN | US | 14th May 1993 |
| 198.135.130.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.131.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.132.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.133.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.134.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.135.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.135.136.0/24 | 256 | ARIN | US | 17th May 1993 |
| 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 |
| 198.135.179.0/24 | 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 |