You need to set up an IPSec failover tunnel for your ASA.
In this example, the primary connection is to Seattle with a failover to Chicago.
This example is made using a Cisco ASA5505 running ASA version 8.4
Step 1: Edit the existing crypto map and add an additional peer. Here you'll add our Chicago data center (18.104.22.168)
Step 2: Create a tunnel group for the secondary peer. You can reuse the same group policy as for the primary:
For testing purposes, you can add a static route for the Seattle data center to an IP address that is not assigned:
NOTE: For a current list of available IPSec gateways, see TECH242979