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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
27,019 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 207.174.203.0/24 | 256 | ARIN | US | 1st Jul 2025 |
| 207.174.208.0/23 | 512 | ARIN | US | 3rd Oct 2025 |
| 207.174.210.0/23 | 512 | ARIN | US | 9th Jun 1999 |
| 207.174.58.0/24 | 256 | ARIN | US | 4th Apr 2023 |
| 207.174.62.0/24 | 256 | ARIN | US | 28th Aug 2023 |
| 207.174.63.0/24 | 256 | ARIN | US | 4th Apr 2023 |
| 207.174.88.0/23 | 512 | ARIN | US | 4th Apr 2023 |
| 207.174.91.0/24 | 256 | ARIN | US | 7th Apr 2023 |
| 207.174.94.0/24 | 256 | ARIN | US | 4th Apr 2023 |
| 207.174.96.0/24 | 256 | ARIN | US | 4th Apr 2023 |
| 207.174.99.0/24 | 256 | ARIN | US | 3rd Apr 2023 |
| 207.182.96.0/19 | 8.2k | ARIN | US | 30th Aug 1996 |
| 207.183.112.0/20 | 4.1k | ARIN | US | 8th Mar 2001 |
| 207.183.192.0/19 | 8.2k | ARIN | US | 18th Oct 1996 |
| 207.183.64.0/19 | 8.2k | ARIN | US | 2nd Oct 1996 |
| 207.183.96.0/20 | 4.1k | ARIN | US | 4th Oct 1996 |
| 207.184.0.0/15 | 131k | ARIN | US | 21st Aug 1996 |
| 207.186.0.0/17 | 32.8k | ARIN | US | 21st Aug 1996 |
| 207.186.192.0/21 | 2k | ARIN | US | 21st Aug 1996 |
| 207.186.200.0/22 | 1k | ARIN | US | 7th Aug 2026 |
| 207.186.208.0/20 | 4.1k | ARIN | US | 21st Aug 1996 |
| 207.188.0.0/22 | 1k | ARIN | US | 22nd Feb 1999 |
| 207.188.16.0/22 | 1k | ARIN | US | 22nd Feb 1999 |
| 207.188.32.0/19 | 8.2k | ARIN | US | 18th Oct 2000 |
| 207.188.5.0/24 | 256 | ARIN | US | 28th Oct 2019 |
| 207.189.144.0/23 | 512 | ARIN | US | 2nd Apr 2020 |
| 207.189.146.0/23 | 512 | ARIN | US | 30th Oct 2020 |
| 207.189.159.0/24 | 256 | ARIN | US | 2nd Aug 2018 |
| 207.189.163.0/24 | 256 | ARIN | US | 25th Jan 2018 |
| 207.189.172.0/22 | 1k | ARIN | US | 10th Nov 2020 |
| 207.189.180.0/24 | 256 | ARIN | US | 2nd Jun 2016 |
| 207.189.182.0/24 | 256 | ARIN | US | 2nd Sept 2016 |
| 207.189.188.0/22 | 1k | ARIN | US | 11th Jul 2014 |
| 207.189.80.0/21 | 2k | ARIN | US | 6th Oct 2000 |
| 207.200.64.0/18 | 16.4k | ARIN | US | 6th Sept 1996 |
| 207.201.128.0/18 | 16.4k | ARIN | US | 16th Sept 1996 |
| 207.207.192.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.194.0/24 | 256 | ARIN | US | 3rd Apr 2026 |
| 207.207.195.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.196.0/22 | 1k | ARIN | US | 14th Oct 1996 |
| 207.207.204.0/23 | 512 | ARIN | US | 14th Oct 1996 |
| 207.207.207.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.211.0/24 | 256 | ARIN | US | 24th Jun 2026 |
| 207.207.212.0/22 | 1k | ARIN | US | 14th Oct 1996 |
| 207.207.216.0/22 | 1k | ARIN | US | 14th Oct 1996 |