My company would like to experiment with a L2 wireless technology from Motorola called Canopy. Canopy creates high-speed, layer 2, point-to-point links in a metro are using antennas with line-of-sight connections to our buildings. We currently have routers, subnets and serial circuits connecting these buildings. I don't want to convert my network to one huge subnet. I would like to keep my subnets and replace the current T1 lines with DSL lines for backup. I need a routing solution that would use the layer 2 links under normal circumstances to connect subnets but could switch to using the DSL and VPN if the Canopy network went down.
I am thinking using a L3 capable switch somehow but I am not sure how.