Passive TCP/IP Fingerprinting January 25, 2022, 10:11:26 pm Passive TCP/IP Fingerprintinghttps://github.com/NikolaiT/zardaxt/Passive TCP/IP Fingerprinting Tool. Run this on your server and find out what Operating Systems your clients are *really* using. https://incolumitas.com/2021/03/13/tcp-ip-fingerprinting-for-vpn-and-proxy-detection/