Load Balancing & Failover Setup:

Network >> Interfaces:
X0 LAN
X1 WAN1
X2 WAN2
 
Network >> Failover & LB
Enable Load Balancing: checked
Type: Basic Failover or Round Robin
Probing >> Probe responder.blobal.sonicwall.com on all interfaces in this group: checked
 
Alternate Setup:
Default LB Group with X1,X2 as Group Members
Preempt failback to preferred interfaces when possible: checked
Logical/Probe Monitoring Enabled: probe succeeds when either main target or alternate target responds
Main target: 8.8.8.8
Alternate target: 4.2.2.2
Default target IP: 204.212.170.23 (Sonicwall)