# Untrust Zone Interface Failover

When there are both primary and backup interfaces bound to the Untrust zone, you can switch traffic from the primary interface to the backup interface, and from the backup to the primary. By default, there is a 30-second interval before the switch over occurs.

An interface failover can occur when ScreenOS detects a physical problem on the primary interface connection, such as an unplugged cable.

You can also configure the device to automatically switch to the backup interface if ScreenOS detects a failure on the primary interface connection. When the connection through the primary interface is restored, ScreenOS automatically switches traffic from the backup interface to the primary.

Note: The interface configuration options you see depend upon the device model and on certain configuration selections, such as the port mode of a device.

Failover checkbox: Select this checkbox to enable failover on the security device.

### Failover Type:

Select one of the following types of interface failover:

- Track IP option enables interface failover when certain IP addresses become unreachable through the interface.

- Tunnel Interface option enables interface failover when certain VPN tunnels on the interface become unreachable through VPN tunnel monitoring. If you select Tunnel Interface, select Edit Weight to assign a weight to each monitored VPN tunnel.

### To Configure Automatic failover

1. Select Automatic Failover.

2. You can optionally change the Failover Holddown Time, which is the interval before the switch over actually occurs. The default is 30 seconds.

3. Click the Apply button.

Click Force to Failover button to switch from the primary interface to the backup interface.

Click Force to Revert button to switch from the backup interface to the primary interface.