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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,427 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 136.175.115.0/24 | 256 | ARIN |  US | 2nd Oct 2020 |
| 136.175.132.0/22 | 1k | ARIN |  CA | 29th Sept 2020 |
| 136.175.140.0/24 | 256 | ARIN | US | 14th Oct 2020 |
| 136.175.148.0/22 | 1k | ARIN | CA | 2nd Oct 2020 |
| 136.175.159.0/24 | 256 | ARIN | US | 1st Oct 2020 |
| 136.175.161.0/24 | 256 | ARIN | US | 22nd Oct 2020 |
| 136.175.162.0/23 | 512 | ARIN | US | 11th Jan 2021 |
| 136.175.188.0/22 | 1k | ARIN | US | 31st Dec 2020 |
| 136.175.2.0/24 | 256 | ARIN | US | 1st Oct 2020 |
| 136.175.200.0/22 | 1k | ARIN | US | 31st Dec 2020 |
| 136.175.204.0/22 | 1k | ARIN | US | 31st Dec 2020 |
| 136.175.212.0/24 | 256 | ARIN | CA | 6th Oct 2025 |
| 136.175.214.0/24 | 256 | ARIN | US | 8th Jan 2021 |
| 136.175.215.0/24 | 256 | ARIN | US | 3rd Apr 2025 |
| 136.175.240.0/24 | 256 | ARIN | US | 7th May 2025 |
| 136.175.241.0/24 | 256 | ARIN | US | 5th Jan 2021 |
| 136.175.254.0/23 | 512 | ARIN | US | 11th Jan 2021 |
| 136.175.26.0/24 | 256 | ARIN | US | 29th Sept 2020 |
| 136.175.27.0/24 | 256 | ARIN | US | 6th Oct 2020 |
| 136.175.44.0/22 | 1k | ARIN | CA | 29th Sept 2020 |
| 136.175.77.0/24 | 256 | ARIN | US | 1st Oct 2020 |
| 136.175.88.0/22 | 1k | ARIN | US | 30th Sept 2020 |
| 136.175.93.0/24 | 256 | ARIN | US | 1st Oct 2020 |
| 136.175.94.0/23 | 512 | ARIN | US | 17th Mar 2026 |
| 136.176.128.0/19 | 8.2k | ARIN | US | 12th Sept 1989 |
| 136.176.224.0/19 | 8.2k | ARIN | US | 12th Sept 1989 |
| 136.18.16.0/23 | 512 | ARIN | US | 30th Aug 2021 |
| 136.18.48.0/23 | 512 | ARIN | US | 30th Aug 2021 |
| 136.180.0.0/16 | 65.5k | ARIN | US | 19th Sept 1989 |
| 136.202.0.0/16 | 65.5k | ARIN | US | 25th Sept 1989 |
| 136.203.0.0/16 | 65.5k | ARIN | US | 25th Sept 1989 |
| 136.22.12.0/22 | 1k | ARIN | US | 9th Nov 2021 |
| 136.22.187.0/24 | 256 | ARIN | US | 1st Aug 2024 |
| 136.22.188.0/22 | 1k | ARIN | US | 1st Aug 2024 |
| 136.22.6.0/23 | 512 | ARIN | US | 30th Mar 2018 |
| 136.228.178.0/23 | 512 | ARIN | US | 4th May 2018 |
| 136.228.188.0/22 | 1k | ARIN | US | 27th Jun 2018 |
| 136.23.128.0/17 | 32.8k | ARIN | US | 1st Aug 2024 |
| 136.237.0.0/16 | 65.5k | ARIN | US | 3rd Oct 1989 |
| 136.240.0.0/15 | 131k | ARIN | US | 5th Oct 1989 |
| 136.245.144.0/20 | 4.1k | ARIN | US | 5th Oct 1989 |
| 136.245.160.0/19 | 8.2k | ARIN | US | 5th Oct 1989 |
| 136.245.192.0/18 | 16.4k | ARIN | US | 5th Oct 1989 |
| 136.8.0.0/15 | 131k | ARIN | US | 29th Nov 2021 |
| 136.96.0.0/13 | 524k | ARIN | US | 1st Aug 2024 |
| 137.102.0.0/16 | 65.5k | ARIN | US | 15th Nov 1989 |
| 137.136.0.0/16 | 65.5k | ARIN | US | 29th Nov 1989 |
| 137.137.0.0/16 | 65.5k | ARIN | US | 29th Nov 1989 |
| 137.167.0.0/16 | 65.5k | ARIN | US | 18th Dec 1989 |
| 137.168.0.0/16 | 65.5k | ARIN | US | 13th Dec 1989 |