Draytek Vigor3910 Series User Manual page 135

Available settings are explained as follows:
Item
Enable High Abailablity
Redundancy Method
Group ID
Priority ID
Authentication Key
Protocol
Management Interface
Vigor3910 Series User's Guide
Description
Check this box to enable HA function.
Select the redundancy method for high availability.
Hot-Standby -
Such method is suitable when there is only one ISP account.
When this method is selected,
During normal operation the secondary router will be

idling. When the primary router fails to operate
normally, the secondary router(s) will take over.
WAN settings of the primary and secondary routers

are identical.
Note: When Hot-Standby is used, the wireless LAN
function on secondary router will be "disabled"
directlly. Clients can not connect to the secondary
router any more.
Active-Standby -
This method is suitable when there are multiple
simultaneously active ISP connections. When this method is
selected,
 All WANs on the secondary routers can be up at the
same time. LANs that are not configured under high
availability can be routed to secondary routers.
 WAN settings of primary and secondary routers are
independently configured.
Config Sync may be enabled to synchronize most

configuration settings between the primary and
secondary routers.
All routers must be set to the same redundancy

method.
Type a value (1~255).
In LAN environment, multiple routers can be devided into
several groups. Each router must be specified with one group
ID. Different routers with the same ID value will be
categoried into the same group.
Only one of the routers in the same group will be selected as
the primary router.
Type a value (1~30).
Different routers must be configured with different IDs.
All routers within a group must be assigned a priority ID.
Within a group, the router with the largest priority ID (i.e.,
the highest priority) will be the primary router. When
multiple routers in a group are assigned the same priority ID,
routers with lower LAN IP addresses (configured on the LAN
>> General Setup page) have higher priority.
Enter an authentication key up to 31 characters long. This is
used to encrypt the DARP (DrayTek Address Redundancy
Protocol) traffic to guard against malicious attacks.
Select the IP protocol to be used for DARP.
Select the interface to be used for DARP negotiation
between routers. Only interfaces which are enabled in
LAN>>General Setup are available for selection.
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