Draytek Vigor3900 User Manual page 309

Item
Settings under
Active-Standby
Vigor3900 Series User's Guide
Description
(master) router once the service is restored.

Delayed – The router must wait for a period of time to
restore to primary (master) router when the service is
restored.
Delayed Interval: Specify the time for waiting.

Manual – Restoring must be done according to the setting
of Manual Preemption Status.
Manual Preemption Status – Click Active or Inactive.
Manual Mode Threshold – Set a period of time for the
system to determine the master router when there is no
master router detected.
If the router is set as Primary (Master) router, and you change
the Manual Preemption Status from Active to Inactive. Once
the router (Primary) detects that it is in Inactive state, it will not
take preemption. However, if there is no secondary router
taking over the service, all the data traffic would be terminated.
To solve the problem, two methods can be executed:
1. Simply reset Manual Preemption Status from Inactive to
Active and then click Apply to save the settings.
2. Set the value for Manual Mode Threshold. After passing the
time configured in Manual Mode Threshold, if the system
detects no master router (primary) router existing, then
Manual Preemption Status will be reset to Active to locate
the master router.
LAN Port Detection Mode – The router (with the role of
Primary - Master) will detect if there is malfunction on LANs
automatically. This function will force the master router to
failover to other backups if any failure of LAN is detected.
There are two schemes to determine the failure of LAN ports:

At Least One Up - The master router can own its position
only if one LAN port is connecting.

All Must Be Up - The master router can own its position
only when all of LAN ports are connecting.
WAN Connection Status Detection –Click Enable to make
the router detecting WAN connection status. It is similar to
"LAN Port Detection Mode" but will detect connection status
of all enabled WAN profiles. If connection status of all enabled
WAN profiles are down, the master router hands off its
position.
Authentication Key – Type a string as the authentication key.
It is used for encrypting the HA session communication to
prevent malicious attack.
WAN Connection Status Detection – Click Enable to make
the router detecting WAN connection status. It is similar to
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