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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.190.40.0/22 | 1k | ARIN |  US | 23rd May 1994 |
| 199.190.64.0/18 | 16.4k | ARIN | US | 19th Oct 2023 |
| 199.191.102.0/23 | 512 | ARIN | US | 25th Feb 2019 |
| 199.191.16.0/20 | 4.1k | ARIN | US | 11th Mar 1994 |
| 199.191.32.0/22 | 1k | ARIN | US | 2nd Dec 1999 |
| 199.191.36.0/24 | 256 | ARIN | US | 2nd Dec 1999 |
| 199.191.37.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.38.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.39.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.48.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.52.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.60.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.63.0/24 | 256 | ARIN | US | 12th Nov 1996 |
| 199.191.64.0/21 | 2k | ARIN | US | 10th Aug 1994 |
| 199.191.72.0/23 | 512 | ARIN | US | 10th Aug 1994 |
| 199.191.76.0/22 | 1k | ARIN | US | 10th Aug 1994 |
| 199.191.96.0/22 | 1k | ARIN | US | 10th Aug 1994 |
| 199.192.216.0/22 | 1k | ARIN | US | 30th Aug 2011 |
| 199.192.220.0/22 | 1k | ARIN | US | 30th Aug 2011 |
| 199.192.240.0/22 | 1k | ARIN | US | 31st Aug 2011 |
| 199.192.252.0/22 | 1k | ARIN | US | 1st Sept 2011 |
| 199.193.12.0/23 | 512 | ARIN | US | 24th Mar 1994 |
| 199.193.152.0/22 | 1k | ARIN | US | 6th Sept 2011 |
| 199.193.176.0/22 | 1k | ARIN | US | 8th Sept 2011 |
| 199.193.184.0/22 | 1k | ARIN | US | 9th Sept 2011 |
| 199.193.30.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.193.31.0/24 | 256 | ARIN | US | 1st Jun 2012 |
| 199.193.57.0/24 | 256 | ARIN | US | 4th Jan 2016 |
| 199.193.8.0/22 | 1k | ARIN | US | 24th Mar 1994 |
| 199.194.0.0/16 | 65.5k | ARIN | US | 7th Mar 1994 |
| 199.195.0.0/22 | 1k | ARIN | US | 24th Mar 1994 |
| 199.195.114.0/23 | 512 | ARIN |  CA | 31st Jul 2015 |
| 199.195.12.0/24 | 256 | ARIN | US | 25th Mar 1994 |
| 199.195.13.0/24 | 256 | ARIN | US | 5th Jun 2012 |
| 199.195.188.0/22 | 1k | ARIN | US | 31st May 2012 |
| 199.195.192.0/21 | 2k | ARIN | US | 1st Jun 2012 |
| 199.195.228.0/22 | 1k | ARIN | CA | 7th Jun 2012 |
| 199.195.232.0/22 | 1k | ARIN | CA | 3rd Oct 2025 |
| 199.195.4.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 199.195.48.0/22 | 1k | ARIN | US | 10th Mar 1994 |
| 199.195.6.0/23 | 512 | ARIN | US | 1st Dec 2016 |
| 199.195.8.0/22 | 1k | ARIN | US | 25th Mar 1994 |
| 199.196.0.0/22 | 1k | ARIN | US | 29th Mar 1994 |
| 199.196.128.0/19 | 8.2k | ARIN | US | 9th Feb 1995 |
| 199.196.16.0/20 | 4.1k | ARIN | US | 9th Mar 1994 |
| 199.196.160.0/20 | 4.1k | ARIN | US | 16th Feb 1995 |
| 199.196.176.0/21 | 2k | ARIN | US | 16th Feb 1995 |
| 199.196.184.0/22 | 1k | ARIN | US | 16th Feb 1995 |
| 199.196.188.0/23 | 512 | ARIN | US | 16th Feb 1995 |
| 199.196.190.0/24 | 256 | ARIN | US | 16th Feb 1995 |