Table of contents: Title Overview Disclaimers Definitions Packet Basics TCP TCP Handshake TCP Handshake Closing TCP Connection Closing TCP Connection UDP ICMP ICMP Diagram Active OS Fingerprinting Nmap and OS Fingerprinting Nmap Techniques Nmap Techniques Nmap Techniques ICMP Error Messages and Nmap Nmapisms Non-nmap Techniques Xprobe Xprobe Techniques Xprobe2 Iptables/Netfilter Iptables Example Dropping a Packet Iptables Ruleset Iptables Test Conditions Iptables Test Setup Successful Xprobe Unsuccessful Xprobe Successful Xprobe2 Unsuccessful Xprobe2 Xprobe/Xprobe2 Countermeasures Successful Nmap Unsuccessful Nmap Nmap Countermeasures Blocking Nmap Portscanning Anti-Nmap Rules Iptables Result Comments Summary
![[CITES]](../../images/cites_home.gif)
![[UIUC]](../../images/iMark_sm.gif)
![[WSG]](../../images/wsg.gif){kind=small}