An active response network tap for use in monitoring a network comprises a first device interface terminal, a second device interface terminal, a first monitor interface terminal, and a second monitor interface terminal. A tap structure is coupled to the first device interface terminal, second device interface terminal, first monitor interface terminal and second monitor interface terminal. A memory is coupled to the tap structure and configured to store data. In one aspect, the tap structure is configured to communicate full-duplex traffic between the tap structure and a monitor device coupled to a monitor interface terminal. In another aspect, the tap structure is configured to insert data from a monitor coupled to the first monitor interface into the traffic between the first device and the second device. Advantages of the invention include the ability to provide monitor access to a network while also supporting communication with other network devices.