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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,279 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 2604:d5c0::/32 | 4.3B × /64 | ARIN |  US | 29th May 2018 |
| 2604:d60::/32 | 4.3B × /64 | ARIN |  CA | 21st Apr 2025 |
| 2604:d640::/32 | 4.3B × /64 | ARIN | US | 29th May 2018 |
| 2604:d740::/32 | 4.3B × /64 | ARIN | US | 30th May 2018 |
| 2604:d80::/32 | 4.3B × /64 | ARIN | US | 23rd Aug 2012 |
| 2604:d830::/32 | 4.3B × /64 | ARIN | US | 2nd Jul 2026 |
| 2604:d860::/32 | 4.3B × /64 | ARIN | US | 24th Dec 2025 |
| 2604:d940::/32 | 4.3B × /64 | ARIN | US | 4th Jun 2018 |
| 2604:da00::/32 | 4.3B × /64 | ARIN |  PR | 2nd Feb 2026 |
| 2604:da0::/32 | 4.3B × /64 | ARIN | US | 21st Apr 2025 |
| 2604:da40::/32 | 4.3B × /64 | ARIN | US | 5th Jun 2018 |
| 2604:dac0::/32 | 4.3B × /64 | ARIN | US | 5th Jun 2018 |
| 2604:db80::/32 | 4.3B × /64 | ARIN | US | 2nd Feb 2026 |
| 2604:dc0::/32 | 4.3B × /64 | ARIN | CA | 20th Jan 2017 |
| 2604:dc40::/32 | 4.3B × /64 | ARIN | US | 12th Jun 2018 |
| 2604:dcc0::/32 | 4.3B × /64 | ARIN | US | 13th Jun 2018 |
| 2604:dd00::/32 | 4.3B × /64 | ARIN | US | 19th May 2011 |
| 2604:dd80::/32 | 4.3B × /64 | ARIN | US | 25th Jul 2013 |
| 2604:ddc0::/32 | 4.3B × /64 | ARIN | US | 20th Jun 2018 |
| 2604:de00::/36 | 268M × /64 | ARIN | US | 29th Nov 2010 |
| 2604:de0::/32 | 4.3B × /64 | ARIN | US | 23rd Apr 2025 |
| 2604:de40::/32 | 4.3B × /64 | ARIN | US | 21st Jun 2018 |
| 2604:de80::/32 | 4.3B × /64 | ARIN | US | 3rd Feb 2026 |
| 2604:dec0::/32 | 4.3B × /64 | ARIN | US | 21st Jun 2018 |
| 2604:df80::/32 | 4.3B × /64 | ARIN | US | 5th Feb 2026 |
| 2604:e040::/32 | 4.3B × /64 | ARIN | US | 25th Jun 2018 |
| 2604:e1c0::/32 | 4.3B × /64 | ARIN | US | 25th Jun 2018 |
| 2604:e240::/32 | 4.3B × /64 | ARIN | US | 26th Jun 2018 |
| 2604:e2c0::/32 | 4.3B × /64 | ARIN | US | 26th Jun 2018 |
| 2604:e300::/32 | 4.3B × /64 | ARIN | US | 20th May 2011 |
| 2604:e340::/32 | 4.3B × /64 | ARIN | US | 26th Jun 2018 |
| 2604:e4c0::/32 | 4.3B × /64 | ARIN | US | 27th Jun 2018 |
| 2604:e640::/32 | 4.3B × /64 | ARIN | US | 3rd Jul 2018 |
| 2604:e680::/32 | 4.3B × /64 | ARIN | US | 6th Aug 2013 |
| 2604:e6c0::/32 | 4.3B × /64 | ARIN | US | 5th Jul 2018 |
| 2604:e80::/32 | 4.3B × /64 | ARIN | CA | 24th Aug 2012 |
| 2604:e900::/32 | 4.3B × /64 | ARIN | US | 24th May 2011 |
| 2604:e940::/32 | 4.3B × /64 | ARIN | US | 19th Jul 2018 |
| 2604:e980::/32 | 4.3B × /64 | ARIN | US | 8th Aug 2013 |
| 2604:ea0::/32 | 4.3B × /64 | ARIN | CA | 29th Apr 2025 |
| 2604:ec40::/32 | 4.3B × /64 | ARIN | CA | 6th Feb 2026 |
| 2604:ec80::/32 | 4.3B × /64 | ARIN | US | 12th Aug 2013 |
| 2604:ed80::/32 | 4.3B × /64 | ARIN | US | 12th Aug 2013 |
| 2604:edc0::/32 | 4.3B × /64 | ARIN | US | 1st Aug 2018 |
| 2604:ee0::/32 | 4.3B × /64 | ARIN | US | 1st May 2025 |
| 2604:eec0::/32 | 4.3B × /64 | ARIN | US | 7th Aug 2018 |
| 2604:efc0::/32 | 4.3B × /64 | ARIN | US | 10th Aug 2018 |
| 2604:f000::/32 | 4.3B × /64 | ARIN | CA | 16th Mar 2010 |
| 2604:f040::/32 | 4.3B × /64 | ARIN | US | 13th Aug 2018 |
| 2604:f080::/32 | 4.3B × /64 | ARIN | US | 19th Aug 2013 |