WSM User Guide - WatchGuard Technologies

About Multiple WAN SupportNoteIf you use multi-WAN in round-robin mode, it is possible to set up round-robin DNS with your DNSprovider to do load-balancing among more than one external interface.About WAN FailoverThis option is also used only on outgoing traffic. If you select this option, the lowest number externalinterface configured in your list becomes the primary external interface. All other external interfaces arebackup external interfaces. The Firebox sends all outgoing traffic to the primary external interface. If theprimary external interface is not active, the Firebox sends traffic to the first backup interface.The Firebox monitors the status of the primary external interface with two procedures. It checks thephysical link status of the interface. It also pings the IP address or domain name of an external host thatyou configure for each interface each 20 seconds. If three pings to this host fail, the Firebox fails over tothe subsequent configured external interface.When the Firebox detects that the primary external interface is active again, it automatically starts tosend new connections to the primary external interface.About multi-WAN with the routing tableWhen you select the routing table option for your multi-WAN configuration, the Firebox uses the routesset in its internal routing table to send packets through the correct external interface. You can set upnetwork or host routes in Policy Manager and the Firebox will examine these routes to see if a packet isto be sent to a specified interface. If the Firebox does not find a specified route, then the Firebox usesthe first default route in its routing table. If the Firebox is configured to use dynamic routing, it sendstraffic based on the dynamic information recorded in its routing table. To see the routing table on theFirebox, connect to Firebox System Manager and select the Status tab.User Guide 103