What is the “TCP Reset” or Bi-Directional feature in a tap and how is it used?
Intrusion Detection Systems (IDS) may have an option to use a feature known as “Active Response” when malicious traffic is detected. If an attacker uses TCP sessions, they can be reset by RST (Reset) packets that are sent to reset one or both hosts in a session from the IDS. In the case of UDP, a session can be broken by sending various ICMP packets to the host from the IDS box. In some cases the IDS may need to use the monitoring NIC for this purpose. Enabling a Bi-directional traffic path in the tap allows the RST packets to renter the network through a tapped copper link. In the case of a tapped fiber link the directional characteristics of fiber taps will not allow this. The “any-to-any” feature of Datacom Systems configurable taps allows the RST packets to be sent out any available extra Monitor port of the tap and enter the network via a local network switch.
