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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,954 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 66.111.96.0/20 | 4.1k | ARIN |  US | 18th Jun 2002 |
| 66.118.32.0/22 | 1k | ARIN |  CA | 4th Oct 2021 |
| 66.118.61.0/24 | 256 | ARIN | US | 20th Oct 2021 |
| 66.118.8.0/22 | 1k | ARIN | US | 4th Oct 2021 |
| 66.119.114.0/23 | 512 | ARIN | US | 21st Nov 2017 |
| 66.129.0.0/19 | 8.2k | ARIN | US | 8th Jun 2001 |
| 66.132.135.0/24 | 256 | ARIN | CA | 8th Aug 2003 |
| 66.132.142.0/23 | 512 | ARIN | CA | 1st Aug 2025 |
| 66.132.146.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.149.0/24 | 256 | ARIN | CA | 8th Aug 2003 |
| 66.132.150.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.154.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.156.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.173.0/24 | 256 | ARIN | CA | 8th Aug 2003 |
| 66.132.174.0/24 | 256 | ARIN | CA | 8th Aug 2003 |
| 66.132.180.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.132.184.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.192.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.196.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.209.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.132.210.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.233.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.132.234.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.236.0/24 | 256 | ARIN | CA | 8th Aug 2003 |
| 66.132.237.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.132.238.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.245.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.132.252.0/23 | 512 | ARIN | CA | 8th Aug 2003 |
| 66.132.255.0/24 | 256 | ARIN | US | 14th May 2024 |
| 66.133.12.0/24 | 256 | ARIN | US | 11th Jul 2001 |
| 66.133.56.0/24 | 256 | ARIN | US | 11th Jul 2001 |
| 66.133.72.0/21 | 2k | ARIN | US | 9th Dec 2015 |
| 66.150.132.0/22 | 1k | ARIN | US | 13th Jul 2001 |
| 66.150.72.0/22 | 1k | ARIN | US | 13th Jul 2001 |
| 66.151.116.0/22 | 1k | ARIN | US | 13th Jul 2001 |
| 66.151.124.0/22 | 1k | ARIN | US | 13th Jul 2001 |
| 66.151.168.0/21 | 2k | ARIN | US | 13th Jul 2001 |
| 66.151.212.0/22 | 1k | ARIN | US | 13th Jul 2001 |
| 66.159.0.0/19 | 8.2k | ARIN | US | 16th Jul 2002 |
| 66.163.208.0/24 | 256 | ARIN | US | 28th Apr 2014 |
| 66.163.215.0/24 | 256 | ARIN | US | 28th Apr 2014 |
| 66.163.216.0/24 | 256 | ARIN | US | 28th Apr 2014 |
| 66.163.220.0/24 | 256 | ARIN | US | 25th Apr 2024 |
| 66.163.222.0/24 | 256 | ARIN | US | 28th Apr 2014 |
| 66.170.112.0/20 | 4.1k | ARIN | US | 18th Aug 2003 |
| 66.171.32.0/23 | 512 | ARIN | US | 12th Feb 2016 |
| 66.171.38.0/24 | 256 | ARIN | US | 12th Feb 2016 |
| 66.171.39.0/24 | 256 | ARIN | US | 28th May 2026 |
| 66.179.0.0/21 | 2k | ARIN | US | 19th Jul 2023 |
| 66.179.103.0/24 | 256 | ARIN | US | 3rd May 2024 |