Now a days lot of application need to receive send data at very high speed almost at the rate at which the ISP provides. The current packet capturing softwarersquos operating system is not able to capture with this speed resulting in loss of packet while capturing. It is a C based library having wrappers for other languages like Perl, Java, Python to utilize it. We need to analyze the existing Libpcap library to find its limitations which would enable us to capture packet at high speed.