High Availability “Active Standby Configuration”
Posted by Edward Eroy on 14 June 2017 01:58 PM
This Application notes will discuss High Availability (HA) using “Active Standby” mode. In the scenario shown here we have three identical routers (Vigor2925) they are deployed in a campus environment where the routers are installed in three different locations for disaster recovery purposes. Routers are installed in Administrator Office, Engineering Office and Information Technology Office. The locations are 1km apart with optic fiber backbone connected to each Vigor2925 LAN port and each location has a separate WAN internet connection. The aim is to provide High Availability at each location. The network topology is shown in the diagram below:
Following routers support High Availability: Vigor2860, Vigor2925, Vigor2952, Vigor2960, Vigor3220 and Vigor3900
Under Normal Operation
Under normal High Availability operation, the traffic from subnet 192.168.1.1 is going through the Primary router which is located in the Information Technology Building.
The Primary Router is Down
In the event the Primary router fails, the remaining routers will send packets to the rest of the HA router group to elect the next Primary router based priority settings. In this diagram above, the Administrator Office Building has higher priority value than Engineering Office Building all traffic is routed to Administrator Office Building.
Two Primary Routers are Down
In the event that two routers have failed (Administrator Office Building and Information Technology Building routers) then traffic will be automatically routed to the Engineering Office Building.
Information Technology Office is out of Commission
In this scenario the entire IT building is out of commission isolating each of the secondary routers from each other. In this scenario they each become Primary routers and run independently of each other. Internet traffic is routed by the corresponding WAN connection to the internet.
High Availability Active Standby Configuration:
Primary Router Configuration
For more details on the High Availability you can visit the link
How to use High Availability
Secondary Router Configuration
Third Router Configuration
How to check the High Availability Status
To know the High Availability status browse to the Virtual IP address 192.168.1.1 and go to Diagnostics >> High Availability Status.
In the table it above, it shows that the router with the IP address of 192.168.1.2 is the Primary router and the two Secondary routers are also online.