A network interface card for filtering transmitted data packet in a network and a method for filtering

A network interface card for filtering a transmitted data packet in a network and a filtering method thereof are provided to reduce a load for analyzing the data packet by analyzing an IP address of the data packet. A network interface card is installed in a network monitoring server for monitoring a local network by mirroring a data packet received from or transmitted to the local network, in order to connect the network monitoring server with the local network. The network interface card includes a MAC(Media Access Control) hardware processing unit(22) analyzes a MAC layer of the data packet, and a calculation unit(24) and a memory(25) for analyzing an IP address layer of the data packet. The data packet passes through the network monitoring server when the IP address of the data packet analyzed by the calculation unit and the memory corresponds to an IP address of an analyzing target server within the local network.