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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
26,295 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 206.83.10.0/24 | 256 | ARIN |  US | 25th Mar 2019 |
| 206.83.12.0/24 | 256 | ARIN | US | 8th May 2019 |
| 206.83.136.0/24 | 256 | ARIN | US | 6th Jan 2020 |
| 206.83.138.0/24 | 256 | ARIN | US | 28th Jan 2020 |
| 206.83.139.0/24 | 256 | ARIN | US | 28th Oct 2025 |
| 206.83.14.0/24 | 256 | ARIN | US | 30th May 2019 |
| 206.83.140.0/24 | 256 | ARIN | US | 2nd Apr 2020 |
| 206.83.141.0/24 | 256 | ARIN | US | 1st May 2020 |
| 206.83.143.0/24 | 256 | ARIN | US | 5th May 2020 |
| 206.83.224.0/22 | 1k | ARIN | US | 14th Sept 1995 |
| 206.83.32.0/21 | 2k | ARIN | US | 13th Sept 1995 |
| 206.83.42.0/24 | 256 | ARIN | US | 25th Jul 2019 |
| 206.83.43.0/24 | 256 | ARIN | US | 8th Aug 2019 |
| 206.83.44.0/24 | 256 | ARIN | US | 21st Aug 2019 |
| 206.88.0.0/13 | 524k | ARIN | US | 9th Aug 1995 |
| 206.96.64.0/19 | 8.2k | ARIN | US | 15th Aug 1995 |
| 206.97.128.0/17 | 32.8k | ARIN | US | 15th Aug 1995 |
| 206.97.24.0/21 | 2k | ARIN | US | 15th Aug 1995 |
| 206.98.0.0/16 | 65.5k | ARIN | US | 15th Aug 1995 |
| 206.99.120.0/21 | 2k | ARIN | US | 15th Aug 1995 |
| 207.100.0.0/16 | 65.5k | ARIN | US | 28th Mar 1996 |
| 207.11.192.0/19 | 8.2k | ARIN | US | 26th Mar 2025 |
| 207.110.64.0/18 | 16.4k | ARIN | US | 24th Apr 1996 |
| 207.111.0.0/18 | 16.4k | ARIN | US | 9th May 1996 |
| 207.115.0.0/18 | 16.4k | ARIN | US | 19th Jun 1996 |
| 207.115.128.0/17 | 32.8k | ARIN | US | 19th Jun 1996 |
| 207.124.0.0/16 | 65.5k | ARIN | US | 1st May 1996 |
| 207.126.224.0/20 | 4.1k | ARIN | US | 5th Mar 2002 |
| 207.126.32.0/21 | 2k | ARIN | US | 8th Apr 1998 |
| 207.146.0.0/15 | 131k | ARIN | US | 6th Jun 1996 |
| 207.149.0.0/16 | 65.5k | ARIN | US | 11th Jun 1996 |
| 207.152.192.0/18 | 16.4k | ARIN | US | 19th Jun 1996 |
| 207.159.192.0/18 | 16.4k | ARIN | US | 2nd Jul 1996 |
| 207.162.224.0/20 | 4.1k | ARIN | US | 25th Feb 1999 |
| 207.166.138.0/24 | 256 | ARIN | US | 24th Jul 1996 |
| 207.166.144.0/24 | 256 | ARIN | US | 3rd Mar 2025 |
| 207.166.146.0/23 | 512 | ARIN | US | 12th Mar 2025 |
| 207.166.148.0/22 | 1k | ARIN | US | 24th Mar 2025 |
| 207.166.27.0/24 | 256 | ARIN | US | 3rd Jul 1996 |
| 207.166.44.0/22 | 1k | ARIN | US | 1st Dec 2016 |
| 207.166.48.0/24 | 256 | ARIN | US | 1st Dec 2016 |
| 207.167.121.0/24 | 256 | ARIN | US | 7th Jan 2022 |
| 207.167.123.0/24 | 256 | ARIN | US | 12th Jan 2022 |
| 207.167.160.0/19 | 8.2k | ARIN | US | 12th Aug 1999 |
| 207.169.0.0/16 | 65.5k | ARIN | US | 9th Nov 2023 |
| 207.170.64.0/18 | 16.4k | ARIN | US | 2nd Aug 1996 |
| 207.174.112.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 207.174.116.0/24 | 256 | ARIN | US | 3rd Apr 2023 |
| 207.174.168.0/22 | 1k | ARIN | US | 4th Jan 2022 |
| 207.174.173.0/24 | 256 | ARIN | US | 6th Oct 1998 |