Open your command prompt (Windows) and execute tracert 1.1.1.1 . Let the routing path fully map out. If you spot multiple private IP hops right at the start (such as addresses starting with 10.x.x.x or 100.64.x.x ), your ISP has restricted you behind a Carrier-Grade NAT.

Based on Parsec’s official documentation and thousands of user reports, the -6023 error can be traced to one or more of these common network issues: