Chapter 9: VRRP Configuration Guide100 SmartSwitch Router User Reference ManualSetting the Backup PriorityAs described in “Multi-Backup Configuration” on page 95, you can specify which Backuprouter takes over when the Master router goes down by setting the priority for the Backuprouters. To set the priority for a Backup router, enter the following command in Configuremode:To specify 200 as the priority used by virtual router 1 on interface int1:The priority can be between 1 (lowest) and 254. The default is 100. The priority for the IPaddress owner is 255 and cannot be changed.Setting the Advertisement IntervalThe VRRP Master router sends periodic advertisement messages to let the other routersknow that the Master is up and running. By default, advertisement messages are sent onceeach second. To change the VRRP advertisement interval, enter the following command inConfigure mode:To set the advertisement interval to 3 seconds:Setting Pre-empt ModeWhen a Master router goes down, the Backup with the highest priority takes over the IPaddresses associated with the Master. By default, when the original Master comes back upagain, it takes over from the Backup router that assumed its role as Master. When a VRRProuter does this, it is said to be in pre-empt mode. Pre-empt mode is enabled by default onthe SSR. You can prevent a VRRP router from taking over from a lower-priority Master bydisabling pre-empt mode. To do this, enter the following command in Configure mode:To prevent a Backup router from taking over as Master from a Master router that has alower priority:Note: If the IP address owner is available, then it will always take over as the Master,regardless of whether pre-empt mode is on or off.ssr(config)# ip-redundancy set vrrp 1 interface int1 priority 200ssr(config)# ip-redundancy set vrrp 1 interface int1 adv-interval 3ssr(config)# ip-redundancy set vrrp 1 interface int1 preempt-mode disabled
