(Through this experiment, we can understand the underlying effect of sniffer, and can capture the data packets generated by the specified network behavior through sniffer, and understand sniffer's message sending and monitoring functions. Through the use of SnifferPro software to master the use of Sniffer (sniffer) tool, and to capture the data packets of FTP, HTTP and other protocols, to understand the data structure of various protocols in the TCP/IP protocol.)