Virtual-WAN-Link

Hi All,

In configuring SD-WAN (WAN load balancing), under "configure system-wan-link", what will be difference between "set fail-alert-interfaces" and "configure fail-alert-interfaces"?

http://help.fortinet.com/cli/fos50hlp/56/Content/FortiOS/fortiOS-cli-ref-56/config/system/virtual-wan-link.htm

I am trying to find out a suitable command to shutdown the LAN port, should both ISPs are down.

Thanks