When you configure the Edge for WAN failover, the Edge sends all traffic through the primary external interface. If the primary interface is not active, the Edge sends all traffic through the secondary external interface. The Firebox X Edge e-Series uses two procedures to see whether the external interface is functional:
The status of the link between the external interface and the device it is connected to (usually a router)
A ping command to a specified location
The Firebox X Edge sends a ping to the default gateway or a computer specified by the administrator. If there is no reply, the Edge changes to the secondary external network interface (WAN2).
When you enable the WAN Failover feature, the Firebox X Edge e-Series does this:
If the WAN1 interface connection stops, the Edge starts to use the WAN2 interface.
If the WAN2 interface connection stops, the Edge starts to use the WAN1 interface.
If the WAN1 interface and the WAN2 interface stop, the Edge tries the two interfaces until it makes a connection.
When the WAN2 interface is in use, the Firebox X Edge monitors the primary (WAN1) interface. When the WAN1 interface becomes available, the Edge automatically goes back to using the WAN1 interface.
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