I want to implement a load balancing. I have 3 ISP and each have a 3 cisco routers. It is connected to one 2900 switch. All of our servers and workstations are private IP addresses and i am using NAT to go out. Right now im just changing all the servers and workstations GW IP to route to different ISP in case one of them goes down. Is there any best solution for this? I just need a guide where to start. I hope you could help me.