In Virtual NIC mode, link statuses of physical interfaces are permanently monitored to detect a link down and a link up. If any link down has been detected in an interface on the active side, and if an interface on the standby side is available, a failover of the transfer path is performed immediately.
Monitoring the link status is started on activation of a virtual interface and stops on deactivation of it. You cannot stop monitoring while a virtual interface is activated.
Point
Immediately after activating a virtual interface, the system waits for 5 seconds until the links of the bundled physical NICs are established. Therefore, a failover is suspended by 5 seconds after detecting an NIC failure.