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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,993 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 45.45.150.0/24 | 256 | ARIN |  US | 21st Jul 2021 |
| 45.45.156.0/24 | 256 | ARIN | US | 31st Jul 2026 |
| 45.45.157.0/24 | 256 | ARIN | US | 21st Jul 2021 |
| 45.45.192.0/24 | 256 | ARIN | US | 10th Aug 2021 |
| 45.59.138.0/24 | 256 | ARIN | US | 8th Jul 2021 |
| 45.59.166.0/24 | 256 | ARIN | US | 8th Jul 2021 |
| 45.59.180.0/22 | 1k | ARIN | US | 29th Sept 2023 |
| 45.61.32.0/20 | 4.1k | ARIN | US | 5th Jan 2015 |
| 45.62.32.0/19 | 8.2k | ARIN | US | 16th Jan 2015 |
| 45.74.152.0/22 | 1k | ARIN | US | 27th May 2026 |
| 45.74.160.0/20 | 4.1k | ARIN | US | 23rd Apr 2015 |
| 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 |
| 45.74.212.0/23 | 512 | ARIN | US | 13th Mar 2026 |
| 45.74.224.0/20 | 4.1k | RIPE NCC | US | 23rd Apr 2015 |
| 45.74.254.0/23 | 512 | ARIN | US | 27th Feb 2026 |
| 45.9.232.0/24 | 256 | ARIN | US | 15th Feb 2024 |
| 46.102.239.0/24 | 256 | RIPE NCC | US | 25th Jun 2010 |
| 46.17.176.0/22 | 1k | ARIN | US | 21st May 2024 |
| 46.173.30.0/23 | 512 | RIPE NCC | US | 20th Jan 2011 |
| 46.183.88.0/21 | 2k | RIPE NCC | US | 7th Dec 2010 |
| 46.22.64.0/20 | 4.1k | RIPE NCC | US | 23rd Nov 2010 |
| 46.228.144.0/20 | 4.1k | RIPE NCC | US | 7th Feb 2011 |
| 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 |
| 48.128.0.0/11 | 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 |
| 48.96.0.0/11 | 2.1M | ARIN | US | 7th Dec 1990 |
| 5.10.232.0/21 | 2k | RIPE NCC | US | 2nd May 2012 |
| 5.104.64.0/21 | 2k | RIPE NCC | US | 28th Jun 2012 |
| 5.179.96.0/20 | 4.1k | ARIN | US | 4th Dec 2024 |
| 5.44.255.0/24 | 256 | RIPE NCC | US | 30th Jul 2021 |
| 5.63.144.0/21 | 2k | RIPE NCC | US | 12th Jun 2012 |
| 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 |
| 51.100.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.164.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.166.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.202.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |
| 51.204.0.0/15 | 131k | RIPE NCC | US | 1st Sept 1993 |