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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.184.252.0/24 | 256 | ARIN |  US | 19th Apr 1994 |
| 199.184.254.0/24 | 256 | ARIN | US | 19th Apr 1994 |
| 199.184.69.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.70.0/23 | 512 | ARIN | US | 27th Jul 1994 |
| 199.184.72.0/23 | 512 | ARIN | US | 27th Jul 1994 |
| 199.184.74.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.75.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.76.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.77.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.78.0/23 | 512 | ARIN | US | 27th Jul 1994 |
| 199.184.8.0/22 | 1k | ARIN | US | 8th Mar 1994 |
| 199.184.82.0/24 | 256 | ARIN | US | 27th Jul 1994 |
| 199.184.84.0/24 | 256 | ARIN | US | 28th Jul 1994 |
| 199.184.86.0/24 | 256 | ARIN | US | 28th Jul 1994 |
| 199.184.87.0/24 | 256 | ARIN | US | 28th Jul 1994 |
| 199.184.90.0/24 | 256 | ARIN | US | 28th Jul 1994 |
| 199.185.13.0/24 | 256 | ARIN | US | 15th Jul 2022 |
| 199.185.97.0/24 | 256 | ARIN | US | 9th Jul 2012 |
| 199.187.0.0/21 | 2k | ARIN | US | 3rd Mar 1994 |
| 199.187.112.0/23 | 512 | ARIN | US | 24th Feb 1994 |
| 199.187.152.0/21 | 2k | ARIN | US | 19th Jul 2011 |
| 199.187.164.0/22 | 1k | ARIN | US | 20th Jul 2011 |
| 199.187.216.0/21 | 2k | ARIN | US | 14th Jul 2022 |
| 199.187.32.0/20 | 4.1k | ARIN | US | 24th Feb 1994 |
| 199.187.48.0/21 | 2k | ARIN | US | 24th Feb 1994 |
| 199.187.56.0/24 | 256 | ARIN | US | 24th Feb 1994 |
| 199.187.57.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 199.187.58.0/23 | 512 | ARIN | US | 4th Oct 1994 |
| 199.187.60.0/22 | 1k | ARIN | US | 4th Oct 1994 |
| 199.187.96.0/20 | 4.1k | ARIN | US | 24th Feb 1994 |
| 199.188.144.0/22 | 1k | ARIN | US | 8th Jul 2026 |
| 199.188.151.0/24 | 256 | ARIN | US | 10th Nov 2021 |
| 199.188.16.0/21 | 2k | ARIN | US | 25th Feb 1994 |
| 199.188.212.0/22 | 1k | ARIN | US | 4th Aug 2011 |
| 199.188.216.0/22 | 1k | ARIN | US | 5th Aug 2011 |
| 199.188.24.0/22 | 1k | ARIN | US | 25th Feb 1994 |
| 199.188.4.0/24 | 256 | ARIN | US | 25th Feb 1994 |
| 199.188.6.0/23 | 512 | ARIN | US | 8th Jul 2015 |
| 199.189.104.0/21 | 2k | ARIN | US | 9th May 2012 |
| 199.189.120.0/22 | 1k | ARIN | US | 9th May 2025 |
| 199.189.136.0/21 | 2k | ARIN | US | 10th Aug 2011 |
| 199.189.144.0/22 | 1k | ARIN | US | 10th Aug 2011 |
| 199.189.152.0/22 | 1k | ARIN | US | 2nd Oct 2023 |
| 199.189.168.0/22 | 1k | ARIN | US | 12th Aug 2011 |
| 199.189.8.0/21 | 2k | ARIN | US | 16th Mar 1994 |
| 199.19.0.0/21 | 2k | ARIN | US | 26th May 2010 |
| 199.19.148.0/22 | 1k | ARIN | US | 27th Jul 2010 |
| 199.19.168.0/22 | 1k | ARIN | US | 25th Nov 2020 |
| 199.19.188.0/22 | 1k | ARIN | US | 29th Jul 2010 |
| 199.19.32.0/20 | 4.1k | ARIN | US | 4th Oct 1993 |