The Gigabit Optical Fail-Open Bypass Kit (the Kit) minimizes the potential risks of in-line Network Security Sensor failure on critical network links. The Gigabit Ethernet (GE) Monitoring ports on Network Security Sensors (Sensors) are fail closed; thus, if the Sensor is deployed in-line, a hardware failure results in network downtime. Fail-open operation for GE ports requires the use of the optional external Bypass Switch provided in the Kit. With the Bypass Switch in place, normal Sensor operation supplies power to the switch via a control cable. While the Sensor is operating, the switch is "on" and routes all traffic directly through the Sensor. When the Sensor fails, the switch automatically shifts to a bypass state: in-line traffic continues to flow through the network link, but is no longer routed through the Sensor. After the Sensor resumes normal operation, the switch returns to the "on" state, once again enabling in-line monitoring. The Kit contains a Bypass Switch and all the connectivity components to connect the switch to the GE Monitoring ports of any Sensor model, and to connect a control cable between the Sensor and the switch.