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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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:b700::/32 | 4.3B × /64 | ARIN |  US | 6th May 2011 |
| 2604:b740::/32 | 4.3B × /64 | ARIN | US | 26th Mar 2018 |
| 2604:b780::/36 | 268M × /64 | ARIN | US | 9th Feb 2016 |
| 2604:b7c0::/32 | 4.3B × /64 | ARIN | US | 26th Mar 2018 |
| 2604:b880::/32 | 4.3B × /64 | ARIN | US | 3rd May 2013 |
| 2604:b8c0::/32 | 4.3B × /64 | ARIN | US | 27th Mar 2018 |
| 2604:b940::/32 | 4.3B × /64 | ARIN | US | 27th Mar 2018 |
| 2604:b9c0::/32 | 4.3B × /64 | ARIN | US | 28th Mar 2018 |
| 2604:ba80::/32 | 4.3B × /64 | ARIN | US | 7th May 2013 |
| 2604:bc00::/32 | 4.3B × /64 | ARIN | US | 7th Jul 2010 |
| 2604:bd00::/32 | 4.3B × /64 | ARIN | US | 9th May 2011 |
| 2604:be00::/32 | 4.3B × /64 | ARIN | US | 23rd Nov 2010 |
| 2604:be80::/32 | 4.3B × /64 | ARIN | US | 14th May 2013 |
| 2604:bec0::/32 | 4.3B × /64 | ARIN | US | 5th Apr 2018 |
| 2604:bf80::/32 | 4.3B × /64 | ARIN | US | 16th May 2013 |
| 2604:c000::/32 | 4.3B × /64 | ARIN | US | 23rd Feb 2010 |
| 2604:c080::/32 | 4.3B × /64 | ARIN | US | 16th May 2013 |
| 2604:c100::/32 | 4.3B × /64 | ARIN | US | 10th May 2011 |
| 2604:c180::/32 | 4.3B × /64 | ARIN | US | 20th May 2013 |
| 2604:c1c0::/32 | 4.3B × /64 | ARIN | US | 10th Apr 2018 |
| 2604:c240::/32 | 4.3B × /64 | ARIN | US | 11th Apr 2018 |
| 2604:c2c0::/32 | 4.3B × /64 | ARIN |  CA | 11th Apr 2018 |
| 2604:c300::/32 | 4.3B × /64 | ARIN | US | 10th May 2011 |
| 2604:c3c0::/32 | 4.3B × /64 | ARIN | US | 12th Apr 2018 |
| 2604:c440::/32 | 4.3B × /64 | ARIN | CA | 12th Apr 2018 |
| 2604:c540::/32 | 4.3B × /64 | ARIN | US | 17th Apr 2018 |
| 2604:c600::/32 | 4.3B × /64 | ARIN | US | 24th Nov 2010 |
| 2604:c640::/32 | 4.3B × /64 | ARIN | US | 19th Apr 2018 |
| 2604:c680::/32 | 4.3B × /64 | ARIN | US | 3rd Jun 2013 |
| 2604:c740::/32 | 4.3B × /64 | ARIN | US | 20th Apr 2018 |
| 2604:c780::/32 | 4.3B × /64 | ARIN | US | 4th Jun 2013 |
| 2604:c940::/32 | 4.3B × /64 | ARIN | US | 30th Apr 2018 |
| 2604:c9c0::/32 | 4.3B × /64 | ARIN |  JM | 3rd May 2018 |
| 2604:ca40::/32 | 4.3B × /64 | ARIN |  PM | 4th May 2018 |
| 2604:cc40::/32 | 4.3B × /64 | ARIN | US | 9th May 2018 |
| 2604:cd80::/32 | 4.3B × /64 | ARIN | US | 24th Jun 2013 |
| 2604:ce40::/32 | 4.3B × /64 | ARIN | US | 10th May 2018 |
| 2604:ce80::/32 | 4.3B × /64 | ARIN | US | 24th Jun 2013 |
| 2604:cec0::/32 | 4.3B × /64 | ARIN | CA | 10th May 2018 |
| 2604:d080::/32 | 4.3B × /64 | ARIN | US | 26th Jun 2013 |
| 2604:d0::/32 | 4.3B × /64 | ARIN | CA | 16th Jan 2025 |
| 2604:d100::/32 | 4.3B × /64 | ARIN | US | 11th May 2011 |
| 2604:d140::/32 | 4.3B × /64 | ARIN | US | 16th May 2018 |
| 2604:d180::/32 | 4.3B × /64 | ARIN | US | 27th Jun 2013 |
| 2604:d1c0::/32 | 4.3B × /64 | ARIN | US | 16th May 2018 |
| 2604:d240::/32 | 4.3B × /64 | ARIN | US | 17th May 2018 |
| 2604:d280::/32 | 4.3B × /64 | ARIN | US | 28th Jun 2013 |
| 2604:d380::/32 | 4.3B × /64 | ARIN | US | 3rd Jul 2013 |
| 2604:d480::/32 | 4.3B × /64 | ARIN | US | 30th Jan 2026 |
| 2604:d500::/32 | 4.3B × /64 | ARIN | US | 13th May 2011 |