Bypass is a connection redundancy or “traffic bypass” feature. It is used as a forced solution when network security hardware fails.
Network security devices are most often used as a filter between two networks, for example, external and internal corporate networks. If for some reason such device fails or goes down, network communication is interrupted. To prevent this from happening, the Bypass mechanism is used, i.e. a direct backup channel is created between the networks, bypassing the filtering device. In the event of a malfunction, the backup bypass is automatically activated, and, due to obvious reasons, the inter-network traffic is no longer filtered.