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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
Browse by registry
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,430 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 2620:f9:4000::/48 | 65.5k × /64 | ARIN |  US | 10th Feb 2016 |
| 2620:f9:8000::/48 | 65.5k × /64 | ARIN | US | 11th Jun 2012 |
| 2620:f9::/44 | 1M × /64 | ARIN | US | 29th Mar 2011 |
| 2620:f9:c000::/48 | 65.5k × /64 | ARIN | US | 10th Feb 2016 |
| 2620:f:2000::/48 | 65.5k × /64 | ARIN | US | 5th Dec 2016 |
| 2620:f:a000::/48 | 65.5k × /64 | ARIN | US | 19th Dec 2016 |
| 2620:f:c000::/48 | 65.5k × /64 | ARIN | US | 30th Nov 2012 |
| 2620:f:e000::/48 | 65.5k × /64 | ARIN | US | 21st Dec 2016 |
| 2620:fa:4000::/48 | 65.5k × /64 | ARIN | US | 23rd Dec 2025 |
| 2620:fa:8000::/48 | 65.5k × /64 | ARIN |  CA | 13th Jun 2012 |
| 2620:fa::/48 | 65.5k × /64 | ARIN | US | 12th Nov 2010 |
| 2620:fa:c000::/48 | 65.5k × /64 | ARIN | US | 17th Feb 2016 |
| 2620:fb:4000::/48 | 65.5k × /64 | ARIN | US | 23rd Feb 2016 |
| 2620:fb:8000::/48 | 65.5k × /64 | ARIN | US | 15th Jun 2012 |
| 2620:fb::/48 | 65.5k × /64 | ARIN | US | 29th Mar 2011 |
| 2620:fc:8000::/48 | 65.5k × /64 | ARIN | US | 15th Jun 2012 |
| 2620:fd:4000::/48 | 65.5k × /64 | ARIN | US | 3rd Mar 2016 |
| 2620:fd::/48 | 65.5k × /64 | ARIN | CA | 30th Mar 2011 |
| 2620:fd:c000::/48 | 65.5k × /64 | ARIN | CA | 4th Mar 2016 |
| 2620:fe:8000::/48 | 65.5k × /64 | ARIN | US | 22nd Jun 2012 |
| 2620:ff:8000::/48 | 65.5k × /64 | ARIN | US | 1st Nov 2013 |
| 2620:ff::/48 | 65.5k × /64 | ARIN | US | 30th Mar 2011 |
| 2630::/16 | 281T × /64 | ARIN | US | 20th Oct 2023 |
| 2631:2000::/24 | 1.1T × /64 | ARIN | US | 2nd Jan 2025 |
| 2631:3000::/24 | 1.1T × /64 | ARIN | US | 10th Apr 2025 |
| 2631:8000::/24 | 1.1T × /64 | ARIN | US | 12th Nov 2025 |
| 2631:a000::/24 | 1.1T × /64 | ARIN | US | 11th May 2026 |
| 31.220.216.0/21 | 2k | ARIN | US | 4th Dec 2024 |
| 31.220.245.0/24 | 256 | ARIN | US | 4th Dec 2024 |
| 31.99.128.0/20 | 4.1k | ARIN | US | 18th May 2026 |
| 31.99.152.0/24 | 256 | ARIN | US | 18th May 2026 |
| 32.144.0.0/12 | 1M | ARIN | US | 25th Sept 2023 |
| 32.240.0.0/15 | 131k | ARIN | US | 23rd Jun 2023 |
| 34.3.2.0/24 | 256 | ARIN | US | 9th May 2022 |
| 35.128.216.0/21 | 2k | ARIN | US | 1st Apr 1994 |
| 35.128.224.0/19 | 8.2k | ARIN | US | 1st Apr 1994 |
| 35.18.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.26.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.28.0.0/14 | 262k | ARIN | US | 8th Feb 2024 |
| 35.34.64.0/20 | 4.1k | ARIN | US | 1st Apr 1994 |
| 35.48.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.52.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.56.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.60.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 36.2.112.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.128.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.224.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.32.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.3.80.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 37.128.192.0/21 | 2k | ARIN | US | 22nd May 2024 |