Have a Cisco ASA 5520 appliance and i would like to configure it to use 2 ISP's for the purpose of load balancing. ISP A is a wireless internet connection with a range of IP addresses and ISP 2 is a SHDSL connection with another range of IP addresses which we've purchased. Both links are with different ISPS. I would like to have both links avaliable at the same time. We do the load balancing via our custom application that the end users use to access our systems externally.
However when they make a connection to our firewall using ISP A the packet must then travel back via the same ISP as well. Same goes with ISP B..
Im alittle stuck on how to acheive this. I havent employed any routing protocols as yet but im open to suggestions. I also have a cisco 1721 router as well with 2 WICS cards and 1 internal interface, so i dont know if i can use this to connect to the two isps, doing some fancy routing then pass the traffic to the ASA appliance..