Virtual Inline Mode and High-Availability
Virtual Inline mode can be used in a high availability (high availability) configuration. The below figure shows a simple high availability deployment. In virtual inline mode, a pair of appliances acts as one virtual appliance. Router configuration is the same for an high availability pair as with a single appliance, except that the Virtual IP address of the high availability pair, not the IP address of an individual appliance, is used in the router configuration tables. In this example, the local appliances must use default virtual inline configuration (Return to Ethernet Sender).
Figure 1. High-availability Example