p0f v3 with impersonation spoofing, written in Python - Accurately guess the OS of a packet with passive fingerprinting.

Network Tools

Purely passive OS and application fingerprinting system

modernized and C99 compliant port of p0f (Passive OS fingerprinting)

Floodspark Counterespionage Firewall (CEF) helps you record and block or honeypot reconnaissance or otherwise illegitimate traffic. CEF is like a web application firewall (WAF) but protects against reconnaissance.

TCP Fingerprinting of email senders.

p0f with Python.

Passive OS fingerprinting support for rspamd

Detecting Network Address Translation & Proxy Use

OS Fringerprinting