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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 2604:800::/32 | 4.3B × /64 | ARIN |  US | 13th Apr 2010 |
| 2604:8040::/32 | 4.3B × /64 | ARIN | US | 13th Nov 2017 |
| 2604:80c0::/32 | 4.3B × /64 | ARIN | US | 15th Nov 2017 |
| 2604:8180::/31 | 8.6B × /64 | ARIN | US | 4th Feb 2014 |
| 2604:8300::/32 | 4.3B × /64 | ARIN | US | 21st Jan 2026 |
| 2604:83c0::/32 | 4.3B × /64 | ARIN | US | 22nd Nov 2017 |
| 2604:8400::/32 | 4.3B × /64 | ARIN |  CA | 29th Jun 2010 |
| 2604:840::/32 | 4.3B × /64 | ARIN | CA | 9th Jan 2017 |
| 2604:8600::/32 | 4.3B × /64 | ARIN | CA | 15th Nov 2010 |
| 2604:860::/32 | 4.3B × /64 | ARIN | US | 14th Mar 2025 |
| 2604:8640::/32 | 4.3B × /64 | ARIN | US | 30th Nov 2017 |
| 2604:8700::/36 | 268M × /64 | ARIN | US | 26th Apr 2011 |
| 2604:8780::/32 | 4.3B × /64 | ARIN | US | 7th Mar 2013 |
| 2604:87c0::/32 | 4.3B × /64 | ARIN | US | 4th Dec 2017 |
| 2604:8840::/32 | 4.3B × /64 | ARIN | US | 5th Dec 2017 |
| 2604:88c0::/32 | 4.3B × /64 | ARIN | US | 5th Dec 2017 |
| 2604:8940::/32 | 4.3B × /64 | ARIN | US | 7th Dec 2017 |
| 2604:8980::/32 | 4.3B × /64 | ARIN | CA | 8th Mar 2013 |
| 2604:8a40::/32 | 4.3B × /64 | ARIN | US | 8th Dec 2017 |
| 2604:8ac0::/32 | 4.3B × /64 | ARIN | US | 12th Dec 2017 |
| 2604:8bc0::/32 | 4.3B × /64 | ARIN | US | 14th Dec 2017 |
| 2604:8c80::/32 | 4.3B × /64 | ARIN |  DM | 13th Mar 2013 |
| 2604:8cc0::/32 | 4.3B × /64 | ARIN | US | 19th Dec 2017 |
| 2604:8e00::/32 | 4.3B × /64 | ARIN | US | 21st Jan 2026 |
| 2604:8e40::/32 | 4.3B × /64 | ARIN | US | 21st Dec 2017 |
| 2604:9040::/32 | 4.3B × /64 | ARIN | US | 27th Dec 2017 |
| 2604:90c0::/32 | 4.3B × /64 | ARIN | US | 28th Dec 2017 |
| 2604:9140::/32 | 4.3B × /64 | ARIN | US | 28th Dec 2017 |
| 2604:91c0::/32 | 4.3B × /64 | ARIN | US | 29th Dec 2017 |
| 2604:920::/32 | 4.3B × /64 | ARIN | CA | 18th Mar 2025 |
| 2604:9280::/32 | 4.3B × /64 | ARIN | US | 19th Mar 2013 |
| 2604:92c0::/32 | 4.3B × /64 | ARIN | US | 10th Jan 2018 |
| 2604:9300::/32 | 4.3B × /64 | ARIN | US | 27th Apr 2011 |
| 2604:9340::/32 | 4.3B × /64 | ARIN | US | 11th Jan 2018 |
| 2604:93c0::/32 | 4.3B × /64 | ARIN | US | 11th Jan 2018 |
| 2604:9480::/32 | 4.3B × /64 | ARIN | US | 21st Mar 2013 |
| 2604:94c0::/32 | 4.3B × /64 | ARIN | US | 17th Jan 2018 |
| 2604:9580::/32 | 4.3B × /64 | ARIN | US | 22nd Jul 2014 |
| 2604:9600::/32 | 4.3B × /64 | ARIN | US | 18th Nov 2010 |
| 2604:9640::/32 | 4.3B × /64 | ARIN | US | 19th Jan 2018 |
| 2604:9680::/32 | 4.3B × /64 | ARIN | US | 28th Jan 2026 |
| 2604:96c0::/32 | 4.3B × /64 | ARIN | US | 19th Jan 2018 |
| 2604:9700::/32 | 4.3B × /64 | ARIN | US | 27th Apr 2011 |
| 2604:9740::/32 | 4.3B × /64 | ARIN | US | 22nd Jan 2018 |
| 2604:97c0::/32 | 4.3B × /64 | ARIN | US | 23rd Jan 2018 |
| 2604:9940::/32 | 4.3B × /64 | ARIN | US | 23rd Jan 2018 |
| 2604:9a80::/32 | 4.3B × /64 | ARIN | US | 28th Mar 2013 |
| 2604:9ac0::/32 | 4.3B × /64 | ARIN | US | 25th Jan 2018 |
| 2604:9b80::/32 | 4.3B × /64 | ARIN | US | 28th Mar 2013 |
| 2604:9bc0::/32 | 4.3B × /64 | ARIN | US | 26th Jan 2018 |