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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,251 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 45.74.180.0/22 | 1k | ARIN |  US | 7th Aug 2026 |
| 45.74.184.0/22 | 1k | ARIN | US | 26th Jun 2026 |
| 45.74.208.0/23 | 512 | ARIN | US | 8th Jul 2026 |
| 45.74.254.0/23 | 512 | ARIN | US | 27th Feb 2026 |
| 45.9.232.0/24 | 256 | ARIN | US | 15th Feb 2024 |
| 46.17.176.0/22 | 1k | ARIN | US | 21st May 2024 |
| 46.23.216.0/21 | 2k | ARIN | US | 3rd Jun 2024 |
| 46.247.104.0/22 | 1k | ARIN | US | 3rd Feb 2025 |
| 48.0.0.0/11 | 2.1M | ARIN | US | 7th Dec 1990 |
| 48.104.0.0/13 | 524k | ARIN | US | 7th Dec 1990 |
| 48.112.0.0/12 | 1M | ARIN | US | 7th Dec 1990 |
| 48.128.0.0/11 | 2.1M | ARIN | US | 17th Jun 2026 |
| 48.32.0.0/13 | 524k | ARIN | US | 7th Dec 1990 |
| 48.40.0.0/14 | 262k | ARIN | US | 7th Dec 1990 |
| 48.48.0.0/12 | 1M | ARIN | US | 7th Dec 1990 |
| 48.64.0.0/12 | 1M | ARIN | US | 7th Dec 1990 |
| 48.80.0.0/12 | 1M | ARIN | US | 17th Jun 2026 |
| 48.96.0.0/14 | 262k | ARIN | US | 7th Dec 1990 |
| 5.179.96.0/20 | 4.1k | ARIN | US | 4th Dec 2024 |
| 50.115.28.0/22 | 1k | ARIN | US | 20th May 2026 |
| 50.115.48.0/20 | 4.1k | ARIN | US | 9th Sept 2011 |
| 50.116.192.0/18 | 16.4k | ARIN | US | 3rd Oct 2011 |
| 50.118.0.0/17 | 32.8k | ARIN | US | 3rd Nov 2011 |
| 50.93.128.0/20 | 4.1k | ARIN | US | 7th Feb 2011 |
| 50.93.192.0/20 | 4.1k | ARIN | US | 8th Feb 2011 |
| 52.119.0.0/24 | 256 | ARIN | US | 27th Apr 2016 |
| 52.119.13.0/24 | 256 | ARIN | US | 1st Jun 2016 |
| 52.119.3.0/24 | 256 | ARIN | US | 13th Nov 2025 |
| 52.124.128.0/17 | 32.8k | ARIN | US | 9th Aug 2016 |
| 52.124.2.0/24 | 256 | ARIN | US | 30th Mar 2016 |
| 52.124.63.0/24 | 256 | ARIN | US | 22nd Mar 2016 |
| 52.128.28.0/24 | 256 | ARIN | US | 4th May 2017 |
| 52.129.128.0/17 | 32.8k | ARIN | US | 9th Aug 2016 |
| 52.129.14.0/23 | 512 | ARIN | US | 4th Feb 2016 |
| 52.129.23.0/24 | 256 | ARIN | US | 7th Mar 2016 |
| 52.132.0.0/14 | 262k | ARIN | US | 24th Nov 2015 |
| 52.144.16.0/21 | 2k | ARIN | US | 4th Apr 2016 |
| 52.144.30.0/24 | 256 | ARIN | US | 2nd Oct 2026 |
| 52.145.0.0/16 | 65.5k | ARIN | US | 24th Nov 2015 |
| 52.223.192.0/18 | 16.4k | ARIN | US | 2nd Sept 2015 |
| 54.1.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.10.0.0/15 | 131k | ARIN | US | 17th Mar 1992 |
| 54.101.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.103.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.105.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.110.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.120.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.125.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.129.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 54.13.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |