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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 199.188.68.0/23 | 512 | ARIN |  CA | 1st May 2012 |
| 199.188.71.0/24 | 256 | ARIN | CA | 1st May 2012 |
| 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 |
| 199.189.236.0/22 | 1k | ARIN | CA | 19th Aug 2011 |
| 199.189.4.0/23 | 512 | ARIN | CA | 8th Mar 1994 |
| 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 |
| 199.19.172.0/22 | 1k | ARIN | CA | 30th Sept 2025 |
| 199.19.188.0/22 | 1k | ARIN | US | 29th Jul 2010 |
| 199.19.32.0/20 | 4.1k | ARIN | US | 4th Oct 1993 |
| 199.19.76.0/23 | 512 | RIPE NCC |  NL | 6th Oct 2011 |
| 199.19.8.0/21 | 2k | ARIN | US | 4th Oct 1993 |
| 199.19.84.0/22 | 1k | ARIN | US | 7th Oct 2011 |
| 199.190.130.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 199.190.132.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 199.190.133.0/24 | 256 | ARIN | US | 11th May 2012 |
| 199.190.135.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.141.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.142.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.143.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.144.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.145.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.146.0/23 | 512 | ARIN | US | 21st Apr 1994 |
| 199.190.148.0/23 | 512 | ARIN | US | 21st Apr 1994 |
| 199.190.150.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.156.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.157.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 199.190.158.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.16.0/20 | 4.1k | ARIN | US | 1st Mar 1994 |
| 199.190.165.0/24 | 256 | ARIN | US | 17th May 2012 |
| 199.190.166.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.167.0/24 | 256 | ARIN | US | 27th Aug 2019 |
| 199.190.168.0/24 | 256 | ARIN | US | 23rd May 2012 |
| 199.190.169.0/24 | 256 | ARIN | US | 22nd Apr 1994 |
| 199.190.170.0/23 | 512 | ARIN | US | 22nd Apr 1994 |
| 199.190.172.0/24 | 256 | ARIN | US | 25th Apr 1994 |