Recursive DNS over TLS over TCP 443

You might want to use an open recursive DNS servers if your ISP's DNS server is lying. However, if your network/ISP is intercepting all DNS requests, a standard open recursive DNS server won't help. You might have more luck by using an alternative port or by forcing the usage of TCP (use-vc option in recent versions of glibc) but it might not work. Alternatively, you could want to talk to a (trusted) remote recursive DNS server over secure channel such as TLS: by using DNS over TLS over TCP port 443 (the HTTP/TLS port), you should be able to avoid most filtering between you and the recursive server.