Active/Passive
— One firewall actively manages
traffic while the other is synchronized and ready to transition
to the active state, should a failure occur. In this mode, both
firewalls share the same configuration settings, and one actively
manages traffic until a path, link, system, or network failure occurs.
When the active firewall fails, the passive firewall transitions
to the active state and takes over seamlessly and enforces the same
policies to maintain network security. Active/passive HA is supported
in the virtual wire, Layer 2, and Layer 3 deployments.