Backup channel through cisco asa?

Question

VPN

Good day colleagues! I ask for advice from experienced ciscars)
There are three offices in different cities, all of them are depleted in L2VPN provided by the provider. There is a task to make a reserve channel through Cisco ASA (costs on each object with white ip). Which VPN technology to use in this case? The problem is that the set is flat on all objects 10.0.0.0/24, how to imitate L2 through ASAs so that if the provider's L2VPN falls off, traffic starts going through ASAs.

Answer 1

How justified is l2 over all points? Translate to l3 and route however you want.
You can try to configure l2vpn between aces (xconnect / pseudowire ..) - and switch over via STP. But it doesn't sound very good.

Answer 2

And what is the criticality of L2?