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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,479 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.175.196.0/24 | 256 | ARIN |  US | 12th Nov 1996 |
| 205.175.208.0/24 | 256 | ARIN | US | 3rd Dec 1999 |
| 205.175.224.0/24 | 256 | ARIN | US | 3rd Dec 1999 |
| 205.175.230.0/23 | 512 | ARIN | US | 12th Nov 1996 |
| 205.175.232.0/22 | 1k | ARIN | US | 12th Nov 1996 |
| 205.175.236.0/23 | 512 | ARIN | US | 12th Nov 1996 |
| 205.175.247.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 205.175.248.0/23 | 512 | ARIN | US | 12th Nov 1996 |
| 205.175.251.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 205.175.252.0/22 | 1k | ARIN | US | 12th Nov 1996 |
| 205.175.32.0/19 | 8.2k | ARIN | US | 23rd Mar 1995 |
| 205.175.64.0/19 | 8.2k | ARIN | US | 3rd Apr 1995 |
| 205.178.148.0/24 | 256 | ARIN |  CA | 9th Apr 2021 |
| 205.178.150.0/23 | 512 | ARIN | US | 9th Apr 2021 |
| 205.178.171.0/24 | 256 | ARIN | US | 12th Apr 2021 |
| 205.178.172.0/22 | 1k | ARIN | US | 8th Mar 2021 |
| 205.184.0.0/19 | 8.2k | ARIN | US | 19th Jul 2000 |
| 205.184.32.0/20 | 4.1k | ARIN | US | 19th Jul 2000 |
| 205.185.224.0/20 | 4.1k | ARIN | US | 10th Aug 2009 |
| 205.187.128.0/19 | 8.2k | ARIN | US | 25th Nov 2024 |
| 205.187.176.0/20 | 4.1k | ARIN | US | 21st Mar 1995 |
| 205.187.192.0/18 | 16.4k | ARIN | US | 21st Mar 1995 |
| 205.189.0.0/24 | 256 | ARIN | US | 2nd Feb 2012 |
| 205.189.100.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.101.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.104.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.106.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.108.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.109.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.110.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.111.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.112.0/22 | 1k | ARIN | US | 22nd Mar 1995 |
| 205.189.118.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.12.0/22 | 1k | ARIN | CA | 22nd Mar 1995 |
| 205.189.120.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.122.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.123.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.124.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.125.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.126.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.128.0/23 | 512 | ARIN | CA | 22nd Mar 1995 |
| 205.189.130.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.131.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.132.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.133.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.136.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.137.0/24 | 256 | ARIN | CA | 29th May 1996 |
| 205.189.138.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.140.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |
| 205.189.142.0/24 | 256 | ARIN | CA | 22nd Mar 1995 |