I currently have a load balancing setup where I have 2 VLANs and 2 WANs.
VLAN 20 connects on WAN 2 (eth2) by default, fails over to WAN 1. WAN 2 is a cellular internet used for VOIP because the DSL is so bad.
LAN (eth1) connects on WAN 1 (eth0) and never under any circumstances connects on WAN 2.
The load-balancing group for VLAN 20 works great and all traffic from it is using WAN 2 by default. The problem Im having is with the primary LAN connection. The only way I could seem to get it to work was to build a second load balancing group and only assign eth0 to it. Then all traffic is sent out over it. This doesn't seem right, but I'm having another issue too. I can't VPN into the router when WAN2 is plugged in. It hangs and then fails saying unable to connect. As soon as I disconnect it, it works.
Most of my configuration is standard. Usually firewall rules, NAT, WAN_IN, WAN_Local, modify firewall rules for the load balancing group, lan-lan exlusion etc. I've deployed this identical configuration on at least 5 other routers, 90% of this configuration on at least 50 routers. The 2 unique aspects of this router are WAN 1 Primary for LAN only/no WAN2, and WAN 2 primary, WAN1 Failover. And never on such a DSL with such a bad upload (150kbps)