Before starting with the my request, Let me explain the current setup:
1. We have ISP A and ISP B connecting to a Cisco 4500 with cat4500-entservicesk9-mz.122-46.SG.bin and WS-X4516-10GE Supervisor/513 MB.
2. We have our own AS and have BGP peering with both ISPs. At present both Network A and B are routed via ISP A and B is backup simple floating static route + AS prepend on ISP B (so you can assume no routes learned from neither of the ISPs).
3. We have 2 Cisco ASA in Active/Passive.
Now we want to have Network B only via ISP B and switch back to A only on failure. What are the options other than using a route map in the existing scenario. If i use any of the BGP metrics to alter the path taken, how do i get this done without getting the routes from the ISP (considering the static routes in place now)
PLease have a look into the attachment for the sketch. Any help is greatly appreciated.