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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 161.36.96.0/21 | 2k | ARIN |  US | 14th May 1992 |
| 161.38.252.0/23 | 512 | ARIN | US | 24th Jul 2024 |
| 161.49.188.0/22 | 1k | ARIN | US | 21st May 1992 |
| 161.51.100.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.51.102.0/23 | 512 | ARIN | US | 27th May 1992 |
| 161.51.104.0/21 | 2k | ARIN | US | 27th May 1992 |
| 161.51.112.0/20 | 4.1k | ARIN | US | 27th May 1992 |
| 161.51.254.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.51.98.0/24 | 256 | ARIN | US | 27th May 1992 |
| 161.60.0.0/16 | 65.5k | ARIN | US | 3rd Jun 1992 |
| 161.63.0.0/16 | 65.5k | ARIN | US | 9th Jun 1992 |
| 161.99.0.0/17 | 32.8k | ARIN | US | 23rd Jun 1992 |
| 162.100.0.0/14 | 262k | ARIN | US | 28th Sept 1992 |
| 162.109.0.0/16 | 65.5k | ARIN | US | 7th Oct 1992 |
| 162.110.0.0/16 | 65.5k | ARIN | US | 13th Oct 1992 |
| 162.113.0.0/16 | 65.5k | ARIN | US | 15th Oct 1992 |
| 162.118.128.0/17 | 32.8k | ARIN | US | 21st Sept 2020 |
| 162.12.0.0/17 | 32.8k | ARIN | US | 30th Jun 1992 |
| 162.12.128.0/18 | 16.4k | ARIN | US | 30th Jun 1992 |
| 162.12.192.0/22 | 1k | ARIN | US | 30th Jun 1992 |
| 162.12.232.0/22 | 1k | ARIN | US | 18th Apr 2017 |
| 162.12.248.0/21 | 2k | ARIN | US | 10th May 2012 |
| 162.120.20.0/24 | 256 | ARIN | US | 12th Jan 2023 |
| 162.120.40.0/22 | 1k | ARIN | US | 14th Mar 2025 |
| 162.120.44.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.120.48.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.120.72.0/23 | 512 | ARIN | US | 21st Jun 2023 |
| 162.120.80.0/22 | 1k | ARIN | US | 4th Aug 1992 |
| 162.124.0.0/16 | 65.5k | ARIN | US | 20th Nov 1992 |
| 162.142.122.0/24 | 256 | ARIN | US | 23rd Apr 2020 |
| 162.142.78.0/24 | 256 | ARIN | US | 5th Aug 2020 |
| 162.143.0.0/16 | 65.5k | ARIN | US | 11th Jan 1993 |
| 162.16.0.0/16 | 65.5k | ARIN | US | 5th Mar 1992 |
| 162.20.0.0/16 | 65.5k | ARIN | US | 9th Jul 1992 |
| 162.208.120.0/22 | 1k | ARIN | US | 11th Oct 2018 |
| 162.208.124.0/22 | 1k | ARIN | US | 17th Mar 2026 |
| 162.208.20.0/22 | 1k | ARIN | US | 25th Mar 2013 |
| 162.210.120.0/21 | 2k | ARIN | US | 24th Apr 2013 |
| 162.210.208.0/22 | 1k | ARIN | US | 26th Apr 2013 |
| 162.210.212.0/24 | 256 | ARIN | US | 26th Apr 2013 |
| 162.210.214.0/23 | 512 | ARIN | US | 26th Apr 2013 |
| 162.211.64.0/22 | 1k | ARIN | US | 3rd May 2013 |
| 162.212.0.0/22 | 1k | ARIN | US | 13th May 2013 |
| 162.212.192.0/22 | 1k | ARIN | US | 22nd May 2013 |
| 162.212.36.0/22 | 1k | ARIN | US | 21st Feb 2020 |
| 162.213.48.0/21 | 2k | ARIN | US | 14th Jun 2018 |
| 162.213.76.0/22 | 1k | ARIN | US | 4th Jun 2013 |
| 162.216.168.0/21 | 2k | ARIN | US | 3rd Jul 2013 |
| 162.216.20.0/22 | 1k | ARIN | US | 19th Jun 2013 |
| 162.216.224.0/23 | 512 | ARIN | US | 10th Jul 2013 |