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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 2604:9c00::/32 | 4.3B × /64 | ARIN |  US | 2nd Jul 2010 |
| 2604:9c40::/32 | 4.3B × /64 | ARIN | US | 29th Jan 2018 |
| 2604:9c80::/32 | 4.3B × /64 | ARIN | US | 29th Mar 2013 |
| 2604:9d00::/32 | 4.3B × /64 | ARIN | US | 29th Apr 2011 |
| 2604:9ec0::/32 | 4.3B × /64 | ARIN | US | 1st Feb 2018 |
| 2604:9f40::/32 | 4.3B × /64 | ARIN | US | 6th Feb 2018 |
| 2604::/32 | 4.3B × /64 | ARIN | US | 29th Jan 2010 |
| 2604:a000::/32 | 4.3B × /64 | ARIN | US | 2nd Mar 2010 |
| 2604:a080::/32 | 4.3B × /64 | ARIN | US | 3rd Apr 2013 |
| 2604:a20::/32 | 4.3B × /64 | ARIN | US | 31st Mar 2025 |
| 2604:a2c0::/32 | 4.3B × /64 | ARIN | US | 13th Feb 2018 |
| 2604:a3c0::/32 | 4.3B × /64 | ARIN |  CA | 16th Feb 2018 |
| 2604:a40::/32 | 4.3B × /64 | ARIN | US | 11th Jan 2017 |
| 2604:a480::/32 | 4.3B × /64 | ARIN | US | 5th Apr 2013 |
| 2604:a4c0::/32 | 4.3B × /64 | ARIN | US | 20th Feb 2018 |
| 2604:a500::/32 | 4.3B × /64 | ARIN | CA | 29th Jan 2026 |
| 2604:a600::/32 | 4.3B × /64 | ARIN | US | 29th Jan 2026 |
| 2604:a60::/32 | 4.3B × /64 | ARIN | US | 4th Apr 2025 |
| 2604:a680::/32 | 4.3B × /64 | ARIN | US | 10th Apr 2013 |
| 2604:a6c0::/32 | 4.3B × /64 | ARIN | US | 22nd Feb 2018 |
| 2604:a700::/32 | 4.3B × /64 | ARIN | US | 2nd May 2011 |
| 2604:a740::/32 | 4.3B × /64 | ARIN | CA | 23rd Feb 2018 |
| 2604:a7c0::/32 | 4.3B × /64 | ARIN | US | 23rd Feb 2018 |
| 2604:a800::/32 | 4.3B × /64 | ARIN | US | 22nd Apr 2010 |
| 2604:a80::/32 | 4.3B × /64 | ARIN | US | 15th Aug 2012 |
| 2604:a8c0::/32 | 4.3B × /64 | ARIN | CA | 26th Feb 2018 |
| 2604:a980::/32 | 4.3B × /64 | ARIN | US | 17th Apr 2013 |
| 2604:a9c0::/32 | 4.3B × /64 | ARIN | US | 27th Feb 2018 |
| 2604:aa00::/32 | 4.3B × /64 | ARIN | US | 22nd Nov 2010 |
| 2604:aa40::/32 | 4.3B × /64 | ARIN | US | 28th Feb 2018 |
| 2604:ab00::/32 | 4.3B × /64 | ARIN | US | 3rd May 2011 |
| 2604:ab40::/32 | 4.3B × /64 | ARIN | US | 2nd Mar 2018 |
| 2604:ac00::/32 | 4.3B × /64 | ARIN | US | 6th Jul 2010 |
| 2604:ac40::/32 | 4.3B × /64 | ARIN | US | 6th Mar 2018 |
| 2604:ac80::/32 | 4.3B × /64 | ARIN | US | 18th Apr 2013 |
| 2604:ad80::/32 | 4.3B × /64 | ARIN | US | 30th Apr 2014 |
| 2604:adc0::/32 | 4.3B × /64 | ARIN | US | 8th Mar 2018 |
| 2604:ae40::/32 | 4.3B × /64 | ARIN | US | 8th Mar 2018 |
| 2604:afc0::/32 | 4.3B × /64 | ARIN | US | 13th Mar 2018 |
| 2604:b00::/32 | 4.3B × /64 | ARIN | US | 10th Jul 2026 |
| 2604:b140::/32 | 4.3B × /64 | ARIN | US | 13th Mar 2018 |
| 2604:b1c0::/32 | 4.3B × /64 | ARIN | US | 14th Mar 2018 |
| 2604:b20::/32 | 4.3B × /64 | ARIN | US | 10th Apr 2025 |
| 2604:b240::/32 | 4.3B × /64 | ARIN | US | 14th Mar 2018 |
| 2604:b280::/32 | 4.3B × /64 | ARIN | CA | 26th Apr 2013 |
| 2604:b4c0::/32 | 4.3B × /64 | ARIN | US | 22nd Mar 2018 |
| 2604:b560::/32 | 4.3B × /64 | ARIN | US | 14th Jul 2026 |
| 2604:b60::/32 | 4.3B × /64 | ARIN | CA | 15th Apr 2025 |
| 2604:b620::/32 | 4.3B × /64 | ARIN | US | 17th Jul 2026 |
| 2604:b6c0::/32 | 4.3B × /64 | ARIN | US | 23rd Mar 2018 |