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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,459 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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: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: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 |
| 2604:f20::/28 | 68.7B × /64 | ARIN | US | 6th May 2025 |
| 2604:f280::/32 | 4.3B × /64 | ARIN | US | 21st Aug 2013 |
| 2604:f2c0::/32 | 4.3B × /64 | ARIN | US | 22nd Aug 2018 |
| 2604:f300::/32 | 4.3B × /64 | ARIN | US | 26th May 2011 |
| 2604:f40::/32 | 4.3B × /64 | ARIN | US | 20th Jan 2017 |
| 2604:f480::/32 | 4.3B × /64 | ARIN | US | 21st Aug 2013 |
| 2604:f500::/32 | 4.3B × /64 | ARIN | US | 27th May 2011 |
| 2604:f5c0::/32 | 4.3B × /64 | ARIN | US | 7th Sept 2018 |
| 2604:f640::/36 | 268M × /64 | ARIN | US | 7th Sept 2018 |
| 2604:f7c0::/32 | 4.3B × /64 | ARIN | US | 18th Sept 2018 |
| 2604:f800::/32 | 4.3B × /64 | ARIN | CA | 26th Apr 2010 |
| 2604:f8c0::/32 | 4.3B × /64 | ARIN | US | 20th Sept 2018 |
| 2604:f940::/32 | 4.3B × /64 | ARIN | US | 21st Sept 2018 |
| 2604:f980::/32 | 4.3B × /64 | ARIN | US | 28th Aug 2013 |
| 2604:fa80::/32 | 4.3B × /64 | ARIN | CA | 28th Aug 2013 |
| 2604:fb00::/32 | 4.3B × /64 | ARIN | US | 27th May 2011 |
| 2604:fb40::/32 | 4.3B × /64 | ARIN | US | 26th Sept 2018 |
| 2604:fc0::/32 | 4.3B × /64 | ARIN | CA | 23rd Jan 2017 |
| 2604:fc40::/32 | 4.3B × /64 | ARIN | US | 9th Feb 2026 |
| 2604:fd40::/32 | 4.3B × /64 | ARIN | US | 2nd Oct 2018 |
| 2604:fdc0::/32 | 4.3B × /64 | ARIN | US | 2nd Oct 2018 |
| 2604:ff00::/32 | 4.3B × /64 | ARIN | US | 31st May 2011 |