To ensure redundancy, you can deploy the VM-Series firewalls on AWS in an active/passive high availability (HA) configuration. The active peer continuously synchronizes its configuration and session information with the identically configured passive peer. A heartbeat connection between the two devices ensures failover if the active device goes down. When the passive peer detects this failure it becomes active and triggers API calls to the AWS infrastructure to move all the dataplane interfaces (ENIs) from the failed peer to itself. The failover time can vary from 20 seconds to over a minute depending on the responsiveness from the AWS infrastructure.