The high-availability function is the function to configure a reliable, high-availability network system.
NS Appliance provides the following functions:
Duplication function
Gateway failsafe function
In order to use this function, NS option licenses for the operating side and standby side are required, as two NS appliances are required.
Prepare one dedicated server for NS appliance on the operating side and another server for NS appliance on the standby side.
Duplication Function
This function involves preparation of two NS appliances, in order to take over operations without continuing L-Platform communications, by the process of the standby NS appliance taking over from the operating NS appliance, even if the operating NS appliance goes down.
Figure 1.13 Overview of the Duplication Function
Gateway failsafe function
This is the function to monitor LAN channels from the NS Appliance to the gateway unit (router unit).
When no response is received to the ICMP Echo request messages which are sent by the NS appliance regularly (monitoring intervals) even after a certain period of time (the response waiting time), the operating NS appliance switches over to the standby NS appliance, as it assumes there is a gateway device problem, or there is a problem with the LAN channels to the gateway device.
Figure 1.14 Overview of the Gateway Failsafe Function
