How to do IP check on VPN in C#?

Question

VPN

How can I do an automatic check of the IP address on a VPN using the site's whois in C#?

Answer 1

Briefly: no way.
In detail:
Send an IP for verification to the site through its API, and then receive a response. See website .
It is worth noting that no IP check guarantees the presence / absence of a VPN. Any layer is hidden, however, perhaps there is "garbage" from it and the proxy. Try to analyze incoming traffic in more detail, as is done when blocking sites. It is also worth considering that a VPN can overwrite absolutely any information except encrypted / user data, so require an ID / verification from the end user. Unfortunately, it is also possible for the end user to forge/overwrite any validation and information in the package. So there is no way to check.