Theory of Operation: The Silicom Bypass Network Interface Cards (NICs) are network cards with paired ports (2 or 4). The pairs either act as a "wire" allowing the network packets to pass or insert the device in between the two ports. When paired with the on-board hardware watchdog or other failsafe, they provide high availability for the network in the face of software outages or maintenance. The software requirements are for a kernel level driver that interfaces with the bypass and watchdog, as well as for control software. User control can be either the provided standalone executable (/bin/bpctl) or the API exposed by the Silicom library.