Lantronix G520 G520 User Guide - Page 107

10: Services Keepalived Services > Keepalived The Keepalived service provides frameworks for load balancing and high availability of the servers connected to the gateway. Keepalived uses Virtual Router Redundancy Protocol (VRRP) to check the health of load balanced routers and elect a router on the network that will serve a particular IP. In a typical configuration, VRRP groups two or more routers into a virtual router, where one router is the master (active) server and the other is the backup node. The master server has a higher priority than the backup server. The master server transmits multicast VRRP advertisement packets at regular intervals, and the backup servers listen for these advertisement packets. If the backup servers fail to receive three consecutive VRRP advertisements, the backup router with the highest priority becomes the new master router so that the system remains functional. The configuration for the backup server will be similar to that of the master server, with the exception of the values for priority, state, and interface, depending on the system hardware configuration. Keepalived Configuration The Keepalived configuration on the web interface includes the following sections:  General - Keepalived log settings  Global - Keepalived global settings  Tracking Scripts - create tracking script blocks that Keepalived will run to determine the health of the host and increase or decrease the priority of the router by the value of the weight.  Tracking Interfaces - configure which interfaces Keepalived will monitor. If a monitored interface fails, Keepalived will adjust the priority of the host according to the configured weight of the tracking interface.  Tracking Processes - create tracking process blocks that Keepalived can use to monitor the health of the router. If the monitored process stops running, Keepalived will adjust the priority of the host according to the weight of the tracking process. After adding a process, you must restart the Keepalived service.  Virtual IP - configure the Virtual IP address for the VRRP instance.  VRRP Instances - add VRRP instances to be run on interfaces that Keepalived is monitoring. The VRRP instance is defined in the General and Advanced settings. The User Notify settings allow Keepalived to run specified scripts when the router transitions between backup and master states. To configure Keepalived settings: 1. Go to Services > Keepalived. 2. Edit the configuration settings. See Table 10-17. 3. Click Save & Apply when you are finished. G520 Series IoT Cellular Gateway User Guide 107