Date: 13-01-03 00:59
what exactly is the issue... you can't load-balance these lines without cooperation from both providers. Yes, you can 'fake' it, but true load-balancing is not possible... so what can you do with this.
you need a private subnet that is common to all systems.
WAN-A gets public traffic, WAN-B is NAT for private LAN as well as secondary DNS and backup MX.
WAN-A will have the default route of WAN-A, WAN-B will have the default route of WAN-B. The private subnet you assign will have access to both, without needing a 'default route' because the subnet is connected. anything on that private will be able to access anything else on that subnet as long as its connected.
you need to give more info, but if you are running vlan capable switches, this type of set up would be easy to setup, keeping the 2 WANs separate, but accessable at al times via the common private subnet.