Alcatel-Lucent OmniSwitch 6850E Series Hardware User's Manual page 134

Roles Within the Stack
Primary
Secondary
!
Offline
Secondary
Offline
Primary
Secondary
Primary
page 6-6
Redundant Management Module Failover (Two Switches)
OmniSwitch 6850E Series Hardware Users Guide
Managing OmniSwitch 6850E Series Stacks
1
A stack of two switches is operating normally. The
stack consists of a primary module and a secondary
module. (The software on both elements in the stack is
synchronized.)
2
The primary management module fails or is taken
offline (e.g., powered off or rebooted by the user).
3 The switch operating as the secondary management module
immediately takes over the primary role. It is at this point
essentially operating as a stand-alone switch.
4
If the switch that previously failed or was taken offline
comes back online, it will assume the secondary role in the
stack.
January 2013