ZyXEL Communications USG40 User Manual page 515

Chapter 31 Device HA
The backup ZyWALL/USG gets the configuration from the master ZyWALL/USG. The backup
ZyWALL/USG cannot become the master or be managed while it applies the new configuration. This
usually takes two or three minutes or longer depending on the configuration complexity.
The following restrictions apply with active-passive mode.
• The master ZyWALL/USG must have no inactive monitored interfaces.
• The backup ZyWALL/USG cannot be the master. This refers to the actual role at the time of
synchronization, not the role setting in the configuration screen.
The backup applies the entire configuration if it is different from the backup's current configuration.
ZyWALL/USG Series User's Guide
515