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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 2604:5040::/32 | 4.3B × /64 | ARIN |  US | 3rd Jul 2017 |
| 2604:5080::/32 | 4.3B × /64 | ARIN | US | 28th Dec 2012 |
| 2604:50c0::/32 | 4.3B × /64 | ARIN | US | 3rd Jul 2017 |
| 2604:5100::/32 | 4.3B × /64 | ARIN | US | 7th Apr 2011 |
| 2604:5140::/32 | 4.3B × /64 | ARIN |  CA | 3rd Jul 2017 |
| 2604:5180::/32 | 4.3B × /64 | ARIN | US | 19th Aug 2026 |
| 2604:5280::/32 | 4.3B × /64 | ARIN | CA | 2nd Jan 2013 |
| 2604:52c0::/32 | 4.3B × /64 | ARIN | US | 6th Jul 2017 |
| 2604:5300::/32 | 4.3B × /64 | ARIN | US | 7th Apr 2011 |
| 2604:5380::/32 | 4.3B × /64 | ARIN | CA | 2nd Jan 2013 |
| 2604:53c0::/32 | 4.3B × /64 | ARIN | US | 7th Jul 2017 |
| 2604:5440::/32 | 4.3B × /64 | ARIN | US | 7th Jul 2017 |
| 2604:54c0::/32 | 4.3B × /64 | ARIN | US | 10th Jul 2017 |
| 2604:5580::/32 | 4.3B × /64 | ARIN | CA | 4th Jan 2013 |
| 2604:560::/32 | 4.3B × /64 | ARIN | US | 25th Feb 2025 |
| 2604:5740::/32 | 4.3B × /64 | ARIN | US | 18th Jul 2017 |
| 2604:5780::/32 | 4.3B × /64 | ARIN | US | 26th Aug 2026 |
| 2604:5840::/32 | 4.3B × /64 | ARIN | US | 28th Aug 2026 |
| 2604:5880::/32 | 4.3B × /64 | ARIN | CA | 7th Jan 2013 |
| 2604:58c0::/32 | 4.3B × /64 | ARIN | US | 19th Jul 2017 |
| 2604:5900::/32 | 4.3B × /64 | ARIN | US | 13th Jan 2026 |
| 2604:59c0::/32 | 4.3B × /64 | ARIN | US | 20th Jul 2017 |
| 2604:5a00::/32 | 4.3B × /64 | ARIN | US | 1st Sept 2026 |
| 2604:5a40::/32 | 4.3B × /64 | ARIN | CA | 25th Jul 2017 |
| 2604:5a80::/32 | 4.3B × /64 | ARIN | US | 14th Jan 2013 |
| 2604:5ac0::/32 | 4.3B × /64 | ARIN | US | 28th Jul 2017 |
| 2604:5b40::/32 | 4.3B × /64 | ARIN | US | 31st Jul 2017 |
| 2604:5bc0::/32 | 4.3B × /64 | ARIN | US | 31st Jul 2017 |
| 2604:5c0::/32 | 4.3B × /64 | ARIN | US | 3rd Jan 2017 |
| 2604:5c40::/32 | 4.3B × /64 | ARIN | CA | 2nd Aug 2017 |
| 2604:5d40::/32 | 4.3B × /64 | ARIN | US | 3rd Aug 2017 |
| 2604:5dc0::/32 | 4.3B × /64 | ARIN | US | 4th Aug 2017 |
| 2604:5e00::/32 | 4.3B × /64 | ARIN | US | 3rd Nov 2010 |
| 2604:5e0::/32 | 4.3B × /64 | ARIN | US | 28th Feb 2025 |
| 2604:5f40::/32 | 4.3B × /64 | ARIN | US | 11th Aug 2017 |
| 2604:5fc0::/32 | 4.3B × /64 | ARIN | US | 14th Aug 2017 |
| 2604:600::/32 | 4.3B × /64 | ARIN | US | 19th Oct 2010 |
| 2604:6100::/32 | 4.3B × /64 | ARIN | US | 11th Apr 2011 |
| 2604:6180::/32 | 4.3B × /64 | ARIN | US | 25th Jan 2013 |
| 2604:6200::/32 | 4.3B × /64 | ARIN | US | 4th Nov 2010 |
| 2604:620::/32 | 4.3B × /64 | ARIN | US | 28th Feb 2025 |
| 2604:6240::/32 | 4.3B × /64 | ARIN | US | 21st Aug 2017 |
| 2604:62c0::/32 | 4.3B × /64 | ARIN | US | 21st Aug 2017 |
| 2604:6380::/32 | 4.3B × /64 | ARIN | US | 30th Jan 2013 |
| 2604:6480::/32 | 4.3B × /64 | ARIN | US | 31st Jan 2013 |
| 2604:6500::/32 | 4.3B × /64 | ARIN | CA | 11th Apr 2011 |
| 2604:6540::/32 | 4.3B × /64 | ARIN | US | 28th Dec 2023 |
| 2604:660::/36 | 268M × /64 | ARIN | US | 3rd Mar 2025 |
| 2604:66c0::/32 | 4.3B × /64 | ARIN | US | 30th Aug 2017 |
| 2604:6700::/32 | 4.3B × /64 | ARIN | US | 14th Apr 2011 |