IntroductionWhat Is Network Analysis and Sniffing?Who Uses Network Analysis?How Are Intruders Using Sniffers?What Does Sniffed Data Look Like?Common Network AnalyzersHow Does It Work?Explaining EthernetUnderstanding the Open Systems Interconnection ModelLayer 1: PhysicalLayer 2: Data LinkThe MAC SublayerThe LLC SublayerLayer 3: NetworkLayer 4: TransportLayer 5: SessionLayer 6: PresentationLayer 7 ApplicationCSMA/CDThe Major Protocols: IP, TCP, UDP, and ICMPIPInternet Control Message ProtocolTCPThe TCP HandshakeTCP SequenceUDPHardware: Cable Taps, Hubs, and SwitchesPort MirroringDefeating SwitchesDetecting SniffersSniffing WirelessHardware RequirementsSoftwareProtocol DissectionDNSNTPHTTPSMTPProtecting Against SniffersNetwork Analysis and PolicySummarySolutions Fast TrackWhat is Network Analysis and Sniffing?Who Uses Network Analysis?How Does it Work?Detecting SniffersProtocol DissectionProtecting Against SniffersNetwork Analysis and PolicyFrequently Asked Questions