Scenario 1 - Two PPPoE connections with Basic Failover Load balancing. Both lines are connected and have IP addresses but one line is not passing any traffic Two lines with the same gateway.
Scenario 2 - Multiple PPPoE WAN connections to different ISPs wherein traffic doesn't pass upon activating the Multiple PPPoE links..
Step 1: Upgrade to the firmware SonicOS 6.1.2.2
Step 2: Navigate to Network | Interfaces and click edit pencil icon for the first WAN interface, for example X1
Step 3: From the Displayed Properties of X1 Interface, click on the Advanced TAB, and Enable "Allow duplicate MAC addresses" checkbox, see screenshot below:
Step 4: repeat the procedure for second WAN Interface and then re negotiate the lines.