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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,249 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 2604:b9c0::/32 | 4.3B × /64 | ARIN | 28th Mar 2018 | |
| 2604:ba80::/32 | 4.3B × /64 | ARIN | 7th May 2013 | |
| 2604:bc00::/32 | 4.3B × /64 | ARIN | 7th Jul 2010 | |
| 2604:bd00::/32 | 4.3B × /64 | ARIN | 9th May 2011 | |
| 2604:bd80::/32 | 4.3B × /64 | ARIN | 27th Oct 2026 | |
| 2604:be00::/32 | 4.3B × /64 | ARIN | 23rd Nov 2010 | |
| 2604:be80::/32 | 4.3B × /64 | ARIN | 14th May 2013 | |
| 2604:bec0::/32 | 4.3B × /64 | ARIN | 5th Apr 2018 | |
| 2604:bf40::/32 | 4.3B × /64 | ARIN | 28th Oct 2026 | |
| 2604:bf80::/32 | 4.3B × /64 | ARIN | 16th May 2013 | |
| 2604:c000::/32 | 4.3B × /64 | ARIN | 23rd Feb 2010 | |
| 2604:c080::/32 | 4.3B × /64 | ARIN | 16th May 2013 | |
| 2604:c100::/32 | 4.3B × /64 | ARIN | 10th May 2011 | |
| 2604:c180::/32 | 4.3B × /64 | ARIN | 20th May 2013 | |
| 2604:c1c0::/32 | 4.3B × /64 | ARIN | 10th Apr 2018 | |
| 2604:c240::/32 | 4.3B × /64 | ARIN | 11th Apr 2018 | |
| 2604:c3c0::/32 | 4.3B × /64 | ARIN | 12th Apr 2018 | |
| 2604:c480::/32 | 4.3B × /64 | ARIN | 10th Nov 2026 | |
| 2604:c540::/32 | 4.3B × /64 | ARIN | 17th Apr 2018 | |
| 2604:c600::/32 | 4.3B × /64 | ARIN | 24th Nov 2010 | |
| 2604:c640::/32 | 4.3B × /64 | ARIN | 19th Apr 2018 | |
| 2604:c680::/32 | 4.3B × /64 | ARIN | 3rd Jun 2013 | |
| 2604:c700::/32 | 4.3B × /64 | ARIN | 13th Nov 2026 | |
| 2604:c740::/32 | 4.3B × /64 | ARIN | 20th Apr 2018 | |
| 2604:c780::/32 | 4.3B × /64 | ARIN | 4th Jun 2013 | |
| 2604:c940::/32 | 4.3B × /64 | ARIN | 30th Apr 2018 | |
| 2604:cc40::/32 | 4.3B × /64 | ARIN | 9th May 2018 | |
| 2604:cd80::/32 | 4.3B × /64 | ARIN | 24th Jun 2013 | |
| 2604:ce40::/32 | 4.3B × /64 | ARIN | 10th May 2018 | |
| 2604:ce80::/32 | 4.3B × /64 | ARIN | 24th Jun 2013 | |
| 2604:d080::/32 | 4.3B × /64 | ARIN | 26th Jun 2013 | |
| 2604:d100::/32 | 4.3B × /64 | ARIN | 11th May 2011 | |
| 2604:d140::/32 | 4.3B × /64 | ARIN | 16th May 2018 | |
| 2604:d180::/32 | 4.3B × /64 | ARIN | 27th Jun 2013 | |
| 2604:d240::/32 | 4.3B × /64 | ARIN | 17th May 2018 | |
| 2604:d280::/32 | 4.3B × /64 | ARIN | 28th Jun 2013 | |
| 2604:d380::/32 | 4.3B × /64 | ARIN | 3rd Jul 2013 | |
| 2604:d400::/32 | 4.3B × /64 | ARIN | 14th Jul 2010 | |
| 2604:d480::/32 | 4.3B × /64 | ARIN | 30th Jan 2026 | |
| 2604:d500::/32 | 4.3B × /64 | ARIN | 13th May 2011 | |
| 2604:d5c0::/32 | 4.3B × /64 | ARIN | 29th May 2018 | |
| 2604:d640::/32 | 4.3B × /64 | ARIN | 29th May 2018 | |
| 2604:d740::/32 | 4.3B × /64 | ARIN | 30th May 2018 | |
| 2604:d80::/32 | 4.3B × /64 | ARIN | 23rd Aug 2012 | |
| 2604:d830::/32 | 4.3B × /64 | ARIN | 2nd Jul 2026 | |
| 2604:d940::/32 | 4.3B × /64 | ARIN | 4th Jun 2018 | |
| 2604:da0::/32 | 4.3B × /64 | ARIN | 21st Apr 2025 | |
| 2604:da40::/32 | 4.3B × /64 | ARIN | 5th Jun 2018 | |
| 2604:dac0::/32 | 4.3B × /64 | ARIN | 5th Jun 2018 | |
| 2604:db80::/32 | 4.3B × /64 | ARIN | 2nd Feb 2026 |