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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
27,007 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 2604:28e0::/32 | 4.3B × /64 | ARIN |  US | 14th Nov 2025 |
| 2604:2920::/32 | 4.3B × /64 | ARIN | US | 18th Nov 2025 |
| 2604:2a60::/32 | 4.3B × /64 | ARIN | US | 19th Nov 2025 |
| 2604:2ae0::/32 | 4.3B × /64 | ARIN | US | 24th Nov 2025 |
| 2604:2b00::/32 | 4.3B × /64 | ARIN | US | 29th Mar 2011 |
| 2604:2b20::/32 | 4.3B × /64 | ARIN | US | 25th Nov 2025 |
| 2604:2b60::/32 | 4.3B × /64 | ARIN | US | 25th Nov 2025 |
| 2604:2be0::/32 | 4.3B × /64 | ARIN | US | 26th Nov 2025 |
| 2604:2c0::/32 | 4.3B × /64 | ARIN | US | 27th Dec 2016 |
| 2604:2c60::/32 | 4.3B × /64 | ARIN | US | 4th Dec 2025 |
| 2604:2c80::/32 | 4.3B × /64 | ARIN | US | 25th Oct 2012 |
| 2604:2cc0::/32 | 4.3B × /64 | ARIN | US | 30th Mar 2017 |
| 2604:2ce0::/32 | 4.3B × /64 | ARIN | US | 9th Dec 2025 |
| 2604:2d20::/32 | 4.3B × /64 | ARIN | US | 11th Dec 2025 |
| 2604:2e0::/32 | 4.3B × /64 | ARIN | US | 10th Feb 2025 |
| 2604:2e40::/32 | 4.3B × /64 | ARIN | US | 3rd Apr 2017 |
| 2604:2f00::/32 | 4.3B × /64 | ARIN | US | 29th Mar 2011 |
| 2604:3100::/32 | 4.3B × /64 | ARIN | US | 29th Mar 2011 |
| 2604:3140::/32 | 4.3B × /64 | ARIN | US | 11th Apr 2017 |
| 2604:3180::/32 | 4.3B × /64 | ARIN | US | 2nd Nov 2012 |
| 2604:31c0::/32 | 4.3B × /64 | ARIN | US | 12th Apr 2017 |
| 2604:3240::/32 | 4.3B × /64 | ARIN | US | 12th Apr 2017 |
| 2604:3300::/32 | 4.3B × /64 | ARIN | US | 31st Mar 2011 |
| 2604:3340::/32 | 4.3B × /64 | ARIN | US | 14th Apr 2017 |
| 2604:33c0::/32 | 4.3B × /64 | ARIN | US | 17th Apr 2017 |
| 2604:3480::/32 | 4.3B × /64 | ARIN | US | 8th Nov 2012 |
| 2604:34c0::/32 | 4.3B × /64 | ARIN | US | 19th Apr 2017 |
| 2604:3580::/32 | 4.3B × /64 | ARIN | US | 8th Nov 2012 |
| 2604:35c0::/32 | 4.3B × /64 | ARIN | US | 2nd Jan 2026 |
| 2604:3600::/32 | 4.3B × /64 | ARIN | US | 26th Oct 2010 |
| 2604:360::/32 | 4.3B × /64 | ARIN | US | 12th Feb 2025 |
| 2604:3640::/32 | 4.3B × /64 | ARIN | US | 20th Apr 2017 |
| 2604:3680::/32 | 4.3B × /64 | ARIN | US | 9th Nov 2012 |
| 2604:3780::/32 | 4.3B × /64 | ARIN | US | 14th Nov 2012 |
| 2604:37c0::/32 | 4.3B × /64 | ARIN | US | 24th Apr 2017 |
| 2604:3800::/32 | 4.3B × /64 | ARIN | US | 16th Apr 2010 |
| 2604:380::/32 | 4.3B × /64 | ARIN | US | 8th Aug 2012 |
| 2604:3880::/32 | 4.3B × /64 | ARIN | US | 3rd Dec 2012 |
| 2604:3980::/32 | 4.3B × /64 | ARIN | US | 13th Aug 2026 |
| 2604:39c0::/32 | 4.3B × /64 | ARIN | US | 27th Apr 2017 |
| 2604:3a40::/32 | 4.3B × /64 | ARIN | US | 19th Aug 2026 |
| 2604:3ac0::/32 | 4.3B × /64 | ARIN | US | 1st May 2017 |
| 2604:3bc0::/32 | 4.3B × /64 | ARIN | US | 2nd May 2017 |
| 2604:3c00::/32 | 4.3B × /64 | ARIN | US | 18th Jun 2010 |
| 2604:3c0::/32 | 4.3B × /64 | ARIN | US | 27th Dec 2016 |
| 2604:3c40::/32 | 4.3B × /64 | ARIN | US | 4th May 2017 |
| 2604:3e80::/32 | 4.3B × /64 | ARIN | US | 10th Dec 2012 |
| 2604:3ec0::/32 | 4.3B × /64 | ARIN | US | 19th Aug 2026 |
| 2604:3f80::/32 | 4.3B × /64 | ARIN | US | 10th Dec 2012 |
| 2604:4040::/32 | 4.3B × /64 | ARIN | US | 16th May 2017 |