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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,434 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 170.225.252.0/22 | 1k | ARIN |  US | 21st Apr 1995 |
| 170.225.32.0/19 | 8.2k | ARIN | US | 21st Apr 1995 |
| 170.225.64.0/19 | 8.2k | ARIN | US | 21st Apr 1995 |
| 170.225.96.0/20 | 4.1k | ARIN | US | 21st Apr 1995 |
| 170.226.0.0/19 | 8.2k | ARIN | US | 21st Apr 1995 |
| 170.226.128.0/17 | 32.8k | ARIN | US | 21st Apr 1995 |
| 170.226.32.0/20 | 4.1k | ARIN | US | 21st Apr 1995 |
| 170.226.48.0/21 | 2k | ARIN | US | 21st Apr 1995 |
| 170.226.58.0/23 | 512 | ARIN | US | 21st Apr 1995 |
| 170.226.60.0/22 | 1k | ARIN | US | 21st Apr 1995 |
| 170.226.64.0/18 | 16.4k | ARIN | US | 21st Apr 1995 |
| 170.227.0.0/16 | 65.5k | ARIN | US | 21st Apr 1995 |
| 170.234.0.0/16 | 65.5k | ARIN | US | 13th May 1994 |
| 170.240.0.0/14 | 262k | ARIN | US | 3rd Mar 1998 |
| 170.248.14.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.248.184.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.248.2.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.249.92.0/22 | 1k | ARIN | US | 6th Mar 2019 |
| 170.251.12.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.140.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.158.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.16.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.168.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.251.56.0/22 | 1k | ARIN | US | 24th Jan 1994 |
| 170.251.62.0/23 | 512 | ARIN | US | 24th Jan 1994 |
| 170.36.0.0/16 | 65.5k | ARIN | US | 3rd Feb 1994 |
| 170.37.200.0/23 | 512 | ARIN | US | 3rd Feb 1994 |
| 170.37.202.0/24 | 256 | ARIN | US | 3rd Feb 1994 |
| 170.37.207.0/24 | 256 | ARIN | US | 3rd Feb 1994 |
| 170.37.208.0/20 | 4.1k | ARIN | US | 3rd Feb 1994 |
| 170.39.0.0/22 | 1k | ARIN | US | 31st Jul 2020 |
| 170.39.100.0/24 | 256 | ARIN |  CA | 3rd Oct 2024 |
| 170.39.137.0/24 | 256 | ARIN | US | 8th Jul 2020 |
| 170.39.188.0/24 | 256 | ARIN | US | 8th Sept 2020 |
| 170.39.189.0/24 | 256 | ARIN | US | 21st Jul 2020 |
| 170.39.205.0/24 | 256 | ARIN | US | 18th Nov 2024 |
| 170.39.229.0/24 | 256 | ARIN | US | 19th Dec 2023 |
| 170.39.248.0/22 | 1k | ARIN | US | 28th Sept 2020 |
| 170.39.40.0/22 | 1k | ARIN | US | 29th Jun 2020 |
| 170.39.44.0/22 | 1k | ARIN | US | 7th Jul 2020 |
| 170.39.56.0/22 | 1k | ARIN | US | 24th Aug 2020 |
| 170.39.6.0/24 | 256 | ARIN | CA | 26th Jun 2020 |
| 170.39.60.0/22 | 1k | ARIN | US | 29th Jun 2020 |
| 170.39.7.0/24 | 256 | ARIN | US | 21st Aug 2020 |
| 170.39.92.0/22 | 1k | ARIN | US | 8th Sept 2020 |
| 170.39.96.0/23 | 512 | ARIN | CA | 1st Jul 2020 |
| 170.4.128.0/19 | 8.2k | ARIN | US | 2nd Dec 1993 |
| 170.4.160.0/21 | 2k | ARIN | US | 2nd Dec 1993 |
| 170.4.208.0/20 | 4.1k | ARIN | US | 2nd Dec 1993 |
| 170.42.0.0/15 | 131k | ARIN | US | 9th Feb 1994 |