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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
27,014 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 216.19.160.0/20 | 4.1k | ARIN |  US | 29th Jun 2001 |
| 216.192.0.0/16 | 65.5k | ARIN | US | 2nd Mar 2000 |
| 216.193.0.0/17 | 32.8k | ARIN | US | 2nd Mar 2000 |
| 216.194.192.0/18 | 16.4k | ARIN | US | 2nd Feb 2001 |
| 216.194.72.0/22 | 1k | ARIN | US | 28th Jan 2026 |
| 216.196.16.0/20 | 4.1k | ARIN | US | 20th Jan 1999 |
| 216.198.65.0/24 | 256 | ARIN | US | 13th Apr 2000 |
| 216.198.67.0/24 | 256 | ARIN | US | 13th Apr 2000 |
| 216.198.72.0/24 | 256 | ARIN | US | 13th Apr 2000 |
| 216.198.74.0/24 | 256 | ARIN | US | 6th Dec 2024 |
| 216.198.75.0/24 | 256 | ARIN | US | 14th Oct 2024 |
| 216.198.84.0/24 | 256 | ARIN | US | 13th Apr 2000 |
| 216.20.168.0/21 | 2k | ARIN | US | 12th Jun 2026 |
| 216.201.96.0/20 | 4.1k | ARIN | US | 19th Sept 2000 |
| 216.203.16.0/22 | 1k | ARIN | US | 18th Aug 1999 |
| 216.203.26.0/23 | 512 | ARIN | US | 23rd Jul 2026 |
| 216.203.30.0/24 | 256 | ARIN | US | 18th Aug 1999 |
| 216.203.32.0/22 | 1k | ARIN | US | 18th Aug 1999 |
| 216.21.0.0/24 | 256 | ARIN | US | 12th Mar 2010 |
| 216.21.16.0/24 | 256 | ARIN | US | 12th Mar 2010 |
| 216.21.20.0/22 | 1k | ARIN | US | 31st Oct 2008 |
| 216.21.239.0/24 | 256 | ARIN | US | 29th Mar 2021 |
| 216.21.241.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 216.21.242.0/23 | 512 | ARIN | US | 1st Jul 2026 |
| 216.21.252.0/22 | 1k | ARIN | US | 1st Jul 2026 |
| 216.21.8.0/22 | 1k | ARIN | US | 14th Apr 2025 |
| 216.211.196.0/24 | 256 | ARIN | US | 7th Apr 2023 |
| 216.211.219.0/24 | 256 | ARIN | US | 6th Apr 2023 |
| 216.213.16.0/21 | 2k | ARIN | US | 9th Aug 2017 |
| 216.216.0.0/15 | 131k | ARIN | US | 19th Nov 2024 |
| 216.219.96.0/20 | 4.1k | ARIN | US | 10th Nov 2000 |
| 216.223.48.0/22 | 1k | ARIN | US | 27th Apr 1999 |
| 216.224.192.0/23 | 512 | ARIN | US | 25th Sept 2006 |
| 216.224.196.0/23 | 512 | ARIN | US | 13th Dec 2013 |
| 216.224.200.0/21 | 2k | ARIN | US | 13th Dec 2013 |
| 216.224.208.0/23 | 512 | ARIN | US | 13th Dec 2013 |
| 216.225.16.0/21 | 2k | ARIN | US | 11th May 1999 |
| 216.225.208.0/20 | 4.1k | ARIN | US | 11th May 1999 |
| 216.230.180.0/22 | 1k | ARIN | US | 1st Apr 2024 |
| 216.230.188.0/22 | 1k | ARIN | US | 1st Apr 2024 |
| 216.230.66.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.8.0/23 | 512 | ARIN | US | 30th May 2018 |
| 216.230.82.0/24 | 256 | ARIN | US | 24th Aug 2020 |
| 216.230.83.0/24 | 256 | ARIN | US | 19th Feb 2015 |
| 216.230.85.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.88.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.230.90.0/24 | 256 | ARIN | US | 14th Jun 1999 |
| 216.234.129.0/24 | 256 | ARIN | US | 16th Jan 2025 |
| 216.234.133.0/24 | 256 | ARIN | US | 30th Apr 2020 |
| 216.234.136.0/24 | 256 | ARIN | US | 23rd Dec 2024 |