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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,149 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.170.40.0/22 | 1k | ARIN |  US | 6th May 1992 |
| 192.170.44.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.46.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.5.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.56.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.58.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.6.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.60.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.61.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.62.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.64.0/22 | 1k | ARIN | US | 6th May 1992 |
| 192.170.68.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.70.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.71.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.72.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.74.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.76.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.78.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.79.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.80.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.81.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.82.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.84.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.85.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.87.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.88.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.89.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.90.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.91.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.92.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.94.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.170.96.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.97.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.170.98.0/23 | 512 | ARIN | US | 6th May 1992 |
| 192.171.114.0/23 | 512 | ARIN |  CA | 17th Mar 2015 |
| 192.171.224.0/19 | 8.2k | ARIN | US | 25th Apr 2013 |
| 192.171.24.0/21 | 2k | ARIN | US | 12th Feb 2016 |
| 192.171.7.0/24 | 256 | ARIN | US | 26th May 1992 |
| 192.172.222.0/24 | 256 | ARIN | US | 10th Jun 1992 |
| 192.172.223.0/24 | 256 | ARIN | US | 10th Jun 1992 |
| 192.172.225.0/24 | 256 | ARIN | US | 23rd Jun 1992 |
| 192.172.227.0/24 | 256 | APNIC |  JP | 27th Jul 1992 |
| 192.172.228.0/24 | 256 | APNIC | JP | 27th Jul 1992 |
| 192.172.229.0/24 | 256 | APNIC | JP | 6th Nov 2007 |
| 192.172.230.0/23 | 512 | APNIC | JP | 7th Nov 2007 |
| 192.172.235.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.241.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.242.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.243.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.247.0/24 | 256 | ARIN | US | 1st Jul 2026 |