Web OS 10.0 Application GuideChapter 11: High Availability n 261212777-A, February 2002When sharing is enabled, the master election process still occurs. Although the process doesnot affect which switch processes packets that must be routed or that are destined for the vir-tual server IP address, it does determine which switch sends advertisements and responds toARP requests sent to the virtual router’s IP address.Web OS strongly recommends that sharing, rather than active-standby configurations, be usedwhenever possible. Sharing offers both better performance and fewer service interruptions inthe face of fault conditions than active-standby configurations.Tracking VRRP Router PriorityWeb OS supports a tracking function that dynamically modifies the priority of a VRRP router,based on its current state. The objective of tracking is to have, whenever possible, the masterbidding processes for various virtual routers in a LAN converge on the same switch. Trackingensures that the selected switch is the one that offers optimal network performance. For track-ing to have any effect on virtual router operation, preemption must be enabled.N OTE – Tracking only affects hot standby and active-standby configurations. It does not haveany effect on active-active sharing configurations.Web OS can track the attributes listed in Table 11-3:Table 11-3 VRRP Tracking ParametersParameter DescriptionNumber of virtual routers in master modeon the switch/cfg/vrrp/track/vrsUseful for ensuring that traffic for any particular cli-ent/server pair is handled by the same switch, increasingrouting and load-balancing efficiency. This parameterinfluences the VRRP router’s priority in both virtual inter-face routers and virtual server routers.Number of IP interfaces active on theswitch/cfg/vrrp/track/ifsHelps elect the virtual routers with the most availableroutes as the master. (An IP interface is considered activewhen there is at least one active port on the same VLAN.)This parameter influences the VRRP router’s priority inboth virtual interface routers and virtual server routers.Number of active ports on the same VLAN/cfg/vrrp/track/portsHelps elect the virtual routers with the most availableports as the master. This parameter influences the VRRProuter’s priority in both virtual interface routers and virtualserver routers.
