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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
27,014 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 216.235.220.0/24 | 256 | ARIN |  US | 6th Oct 2025 |
| 216.235.223.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 216.235.252.0/22 | 1k | ARIN | US | 30th Jan 2026 |
| 216.237.29.0/24 | 256 | ARIN | US | 15th Sept 1999 |
| 216.237.56.0/24 | 256 | ARIN | US | 15th Sept 1999 |
| 216.238.44.0/22 | 1k | ARIN | US | 1st Jul 2025 |
| 216.24.0.0/20 | 4.1k | ARIN | US | 21st Jul 1998 |
| 216.24.16.0/21 | 2k | ARIN | US | 21st Jul 1998 |
| 216.24.24.0/22 | 1k | ARIN | US | 21st Jul 1998 |
| 216.24.28.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.30.0/23 | 512 | ARIN | US | 21st Jul 1998 |
| 216.24.33.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.35.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.36.0/22 | 1k | ARIN | US | 21st Jul 1998 |
| 216.24.42.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.46.0/24 | 256 | ARIN | US | 8th Jul 2019 |
| 216.24.48.0/23 | 512 | ARIN | US | 21st Jul 1998 |
| 216.24.50.0/24 | 256 | ARIN | US | 21st Jul 1998 |
| 216.24.54.0/24 | 256 | ARIN | US | 26th May 2020 |
| 216.24.55.0/24 | 256 | ARIN | US | 4th Feb 2019 |
| 216.24.62.0/24 | 256 | ARIN | US | 2nd Dec 2020 |
| 216.240.96.0/20 | 4.1k | ARIN | US | 20th Sept 1999 |
| 216.243.80.0/20 | 4.1k | ARIN | US | 27th May 2005 |
| 216.245.130.0/23 | 512 | ARIN | US | 1st Jun 2023 |
| 216.245.160.0/20 | 4.1k | ARIN | US | 19th Jul 2023 |
| 216.245.68.0/24 | 256 | ARIN | US | 8th Dec 2020 |
| 216.245.69.0/24 | 256 | ARIN | US | 10th Oct 1999 |
| 216.246.203.0/24 | 256 | ARIN | US | 10th Oct 2003 |
| 216.247.120.0/21 | 2k | RIPE NCC | US | 21st Oct 1999 |
| 216.247.236.0/24 | 256 | ARIN | US | 20th Dec 2021 |
| 216.247.254.0/24 | 256 | ARIN | US | 24th Jan 2022 |
| 216.248.240.0/20 | 4.1k | ARIN | US | 27th Mar 2026 |
| 216.249.20.0/22 | 1k | ARIN | US | 24th Jan 2001 |
| 216.249.24.0/21 | 2k | ARIN | US | 24th Jan 2001 |
| 216.250.16.0/20 | 4.1k | ARIN | US | 22nd Jan 2004 |
| 216.250.160.0/19 | 8.2k | ARIN | US | 8th Nov 1999 |
| 216.250.247.0/24 | 256 | ARIN | US | 17th Aug 2020 |
| 216.250.48.0/20 | 4.1k | ARIN | US | 20th Mar 2003 |
| 216.251.112.0/20 | 4.1k | ARIN | US | 17th Mar 2003 |
| 216.252.155.0/24 | 256 | ARIN | US | 13th Sept 2022 |
| 216.252.240.0/20 | 4.1k | ARIN | US | 18th Nov 2022 |
| 216.255.128.0/19 | 8.2k | ARIN | US | 30th Apr 2001 |
| 216.255.64.0/19 | 8.2k | ARIN | US | 16th Apr 2001 |
| 216.26.80.0/20 | 4.1k | ARIN | US | 2nd Mar 2001 |
| 216.30.160.0/20 | 4.1k | ARIN | US | 15th Nov 2002 |
| 216.31.208.0/20 | 4.1k | ARIN | US | 23rd Oct 2002 |
| 216.38.104.0/22 | 1k | ARIN | US | 5th Jul 2006 |
| 216.38.108.0/23 | 512 | ARIN | US | 5th Jul 2006 |
| 216.38.110.0/24 | 256 | ARIN | US | 5th Jul 2006 |
| 216.38.96.0/21 | 2k | ARIN | US | 5th Jul 2006 |