SonicWALL Internet Security Appliances - Manual (Page 230)

High Availability Page 231
The first line in the status window indicates that the backup SonicWALL is currently Active. It is also
possible to check the status of the backup SonicWALL by logging into the LAN IP Address of the
backup SonicWALL. If the primary SonicWALL is operating normally, the status window indicates
that the backup SonicWALL is currently Idle. If the backup has taken over for the primary, this
window indicates that the backup is currently Active.
Tip In the event of a failure in the primary SonicWALL, you can access the Web Management
Interface of the backup SonicWALL at the primary SonicWALL LAN IP Address or at the backup
SonicWALL LAN IP Address. When the primary SonicWALL restarts after a failure, it is accessible
using the third IP address created during configuration. If preempt mode is enabled, the primary
SonicWALL becomes the active firewall and the backup firewall returns to idle status.
E-mail Alerts Indicating Status Change
If you have configured the primary SonicWALL to send E-mail alerts, you receive alert E-mails when
there is a change in the status of the High Availability pair. For example, when the backup
SonicWALL takes over for the primary after a failure, an E-mail alert is sent indicating that the
backup has transitioned from Idle to Active. If the primary SonicWALL subsequently resumes
operation after that failure, and Preempt Mode has been enabled, the primary SonicWALL takes
over and another E-mail alert is sent to the administrator indicating that the primary has pre-empted
the backup.