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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
26,951 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 207.186.0.0/18 | 16.4k | ARIN | US | 21st Aug 1996 |
| 207.186.208.0/20 | 4.1k | ARIN | US | 21st Aug 1996 |
| 207.186.64.0/20 | 4.1k | ARIN | US | 21st Aug 1996 |
| 207.186.96.0/19 | 8.2k | ARIN | US | 4th Nov 2026 |
| 207.188.0.0/23 | 512 | ARIN | US | 29th Sept 2026 |
| 207.188.17.0/24 | 256 | ARIN | US | 26th Oct 2026 |
| 207.188.18.0/23 | 512 | ARIN | US | 30th Oct 2026 |
| 207.188.24.0/23 | 512 | ARIN | US | 5th Nov 2026 |
| 207.188.26.0/23 | 512 | 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 |
| 207.189.180.0/24 | 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 | 28th Aug 2026 |
| 207.207.195.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.196.0/23 | 512 | ARIN | US | 14th Oct 1996 |
| 207.207.198.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.199.0/24 | 256 | ARIN | US | 21st Oct 2026 |
| 207.207.204.0/24 | 256 | 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 |
| 207.207.220.0/23 | 512 | ARIN | US | 14th Oct 1996 |
| 207.207.223.0/24 | 256 | ARIN | US | 14th Oct 1996 |
| 207.207.224.0/20 | 4.1k | ARIN | US | 14th Oct 1996 |
| 207.207.248.0/23 | 512 | ARIN | US | 14th Oct 1996 |
| 207.210.122.0/23 | 512 | ARIN | US | 26th Nov 2018 |
| 207.210.76.0/22 | 1k | ARIN | US | 12th Apr 2005 |
| 207.210.93.0/24 | 256 | ARIN | US | 12th Apr 2005 |
| 207.210.94.0/24 | 256 | ARIN | US | 12th Apr 2005 |
| 207.210.97.0/24 | 256 | ARIN | US | 12th Apr 2005 |
| 207.211.216.0/21 | 2k | ARIN | US | 3rd Oct 1996 |
| 207.22.192.0/18 | 16.4k | ARIN | US | 27th Dec 2006 |
| 207.221.128.0/17 | 32.8k | ARIN | US | 16th Oct 1996 |
| 207.221.32.0/19 | 8.2k | ARIN | US | 16th Oct 1996 |
| 207.221.64.0/18 | 16.4k | ARIN | US | 16th Oct 1996 |
| 207.222.128.0/19 | 8.2k | ARIN | US | 16th Oct 1996 |
| 207.222.176.0/20 | 4.1k | ARIN | US | 16th Oct 1996 |