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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,283 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 2604:1e0::/32 | 4.3B × /64 | ARIN |  US | 31st Jan 2025 |
| 2604:1e20::/32 | 4.3B × /64 | ARIN | US | 21st Aug 2025 |
| 2604:1e40::/32 | 4.3B × /64 | ARIN | US | 1st Mar 2017 |
| 2604:1e60::/32 | 4.3B × /64 | ARIN | US | 23rd Aug 2025 |
| 2604:1ea0::/32 | 4.3B × /64 | ARIN | US | 25th Aug 2025 |
| 2604:1fa0::/32 | 4.3B × /64 | ARIN | US | 4th Sept 2025 |
| 2604:1fc0::/32 | 4.3B × /64 | ARIN | US | 6th Mar 2017 |
| 2604:20e0::/32 | 4.3B × /64 | ARIN | US | 18th Sept 2025 |
| 2604:2120::/32 | 4.3B × /64 | ARIN | US | 19th Sept 2025 |
| 2604:2140::/32 | 4.3B × /64 | ARIN | US | 7th Mar 2017 |
| 2604:2160::/32 | 4.3B × /64 | ARIN | US | 22nd Sept 2025 |
| 2604:21a0::/32 | 4.3B × /64 | ARIN | US | 23rd Sept 2025 |
| 2604:21e0::/32 | 4.3B × /64 | ARIN | US | 24th Sept 2025 |
| 2604:220::/32 | 4.3B × /64 | ARIN | US | 31st Jan 2025 |
| 2604:2260::/32 | 4.3B × /64 | ARIN | US | 25th Sept 2025 |
| 2604:22c0::/32 | 4.3B × /64 | ARIN | US | 10th Mar 2017 |
| 2604:2320::/32 | 4.3B × /64 | ARIN | US | 29th Sept 2025 |
| 2604:2480::/32 | 4.3B × /64 | ARIN | US | 12th Oct 2012 |
| 2604:24a0::/32 | 4.3B × /64 | ARIN | US | 14th Oct 2025 |
| 2604:2520::/32 | 4.3B × /64 | ARIN | US | 15th Oct 2025 |
| 2604:25a0::/32 | 4.3B × /64 | ARIN | US | 16th Oct 2025 |
| 2604:2660::/32 | 4.3B × /64 | ARIN | US | 22nd Oct 2025 |
| 2604:2680::/32 | 4.3B × /64 | ARIN | US | 15th Oct 2012 |
| 2604:2720::/32 | 4.3B × /64 | ARIN | US | 29th Oct 2025 |
| 2604:2740::/32 | 4.3B × /64 | ARIN | US | 21st Mar 2017 |
| 2604:2760::/32 | 4.3B × /64 | ARIN | US | 31st Oct 2025 |
| 2604:2780::/32 | 4.3B × /64 | ARIN | US | 15th Oct 2012 |
| 2604:27a0::/32 | 4.3B × /64 | ARIN | US | 3rd Nov 2025 |
| 2604:27c0::/32 | 4.3B × /64 | ARIN | US | 21st Mar 2017 |
| 2604:27e0::/32 | 4.3B × /64 | ARIN | US | 4th Nov 2025 |
| 2604:2860::/32 | 4.3B × /64 | ARIN | US | 13th Nov 2025 |
| 2604:28a0::/32 | 4.3B × /64 | ARIN | US | 14th Nov 2025 |
| 2604:28c0::/32 | 4.3B × /64 | ARIN | US | 23rd Mar 2017 |
| 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 |