An update to my original BSD Dual wan routing guide showing the basic configuration requirements for load balancing Internet connections on version 1.2.3 of pfSense. The last dual wan routing guide was based on an early alpha so things are a lot more stable and quite simply just work. The old days of failed load balancing attempts are long gone. The bottom line is that if you are looking for load balancing software you can stop once you have found pfSense and say goodbye to load balancing switch hardware.
Assuming you already have your links setup there are only two real steps required for most setups, start by configuring your load balancing rule, go to load balancing under the services menu and fill in the details, set your monitor ip to match the gateways as you add them. (to do ratios add gateways more than once to weight them in the round robin)
Then you simply need to edit your default firewall rule to use the balancer, automatic outbound nat works on the newer versions (unlike my guide from alpha) of pfsense but if you are running manual nat you will simply need to add the rules there to make everything work.
And there you have it, a dual wan load balancing router with fail over in under 5 minutes and without the price tag of a house, huge thank you the pfsense team for creating an awesome load balancing router which offers an easy way to bond Internet connections without spending a fortune on a load balancing switch or some other expensive way to achieve wan load balancing