Network Sniffer: A Sniffer is a software that grabs all of the traffic flowing into and out of a computer attached to a network. They supports several platforms in both commercial and open-source variations. Some of simplest packages are actually quite easy to implement in C or Perl, use a command line interface and dump captured data to the screen. More complex projects use a GUI, graph traffic statistics, track multiple sessions and offer several configuration options. Intrusion Detection Systems (IDS) use sniffers to match packets against a rule-set designed to flag anything malicious or strange. Law enforcement agencies that need to monitor email during investigations, likely employ a sniffer designed to capture very specific traffic.
Here are the download link for different Sniffers .....
Download Ettercap
Whos.On.My.WiFi
SoftPerfect Network Protocol Analyzer
Wireless Sniffing with Netmon 3.4
Network Miner
