This thread seems to discuss the problem. True connection load balancing
seems to require expensive hardware and ISP support (for BGP or OSPF),
but this might work...
pmok at optushome dot com dot au wrote:
> Sorry dude, m0n0wall does NOT have Load Balancing capability. It'll take
> quite a while to implement and perfect this. It may or may not be a feature
> in the future, but not now.