Dell PowerConnect FCS624S Configuration Guide - Page 218

5 PowerConnect B-Series FCX hitless stacking Hitless stacking failover example Figure 18 illustrates hitless stacking failover operation when the Active Controller fails. FIGURE 18 Hitless stacking failover when the Active Controller fails The stack comes back without the Active con. troller Active 1 Member 2 = bootup Standby Member 3 1 Member 4 The Active controller fails after the stack reloads Member 2 = bootup Standby Member 3 1 Member 4 The bootup Standby will become the Active controller in 50 seconds. The stack will not reload. 50 sec. Active 2 Member 3 1 Member 4 30-60 sec. Active 2 Standby 3 1 Member 4 Hitless stacking switchover Hitless stacking switchover is a manually-controlled (CLI-driven) or automatic switchover of the Active and Standby Controllers without reloading the stack and without any packet loss to the services and protocols that are supported by hitless stacking. A switchover is activated by the CLI command stack switch-over. A switchover might also be activated by the CLI command priority, depending on the configured priority value. By default, hitless switchover is not allowed. The default behavior is described in "Hitless stacking default behavior" on page 173. Hitless switchover can be used by a system administrator, for example, to perform maintenance on a controller that has been functioning as the Active Controller. For a description of the events that occur during a hitless stacking switchover, refer to "What happens during a hitless stacking switchover or failover" on page 166. 176 PowerConnect B-Series FCX Configuration Guide 53-1002266-01