Brocade FastIron Ethernet Switch Stacking Configuration Guide - Manual (Page 106)

If more than one unit in the stack meets this criteria, the standby controller is chosen according to the
following criteria, in the order shown:
• Priority - The unit with the highest priority value.
• Current standby - The unit that is currently the standby controller.
• Bootup master - The unit that was the active controller before the stack was reloaded.
• Bootup standby - The unit that was the standby controller before the stack was reloaded.
Once the standby controller is identified, the following internal events take place.
1. The standby controller is assigned by the active controller 30 to 60 seconds after election (60
seconds if the active controller boots up in less than 120 seconds).
2. The standby controller receives and processes the runtime configuration sent by the active
controller.
3. The standby controller learns the protocols within 70 seconds.
When the standby controller is fully synchronized, the system will be ready for a switchover or
failover.
Runtime configuration mismatch
In some cases, such as a runtime configuration mismatch between the active controller and candidate
standby controller, the standby controller cannot be assigned by the active controller unless the
candidate standby controller is reloaded.
As shown in the following example, the show stack command output will indicate whether there is a
runtime configuration mismatch.
device#show stack
alone: standalone, D: dynamic config, S: static config
ID Type Role MAC Address Pri State Comment
1 S FCX624S active 0000.0001.0000 30 local Ready
2 d FCX648SPOE member 0000.0002.0000 20 remote Ready, standby if reload
active
+---+ +---+
-2/1| 2 |2/2--2/1| 1 |2/2-
+---+ +---+
Note: There is no standby. Reason: u2: diff runtime config
Current stack management MAC is 0000.0001.0000
Note: no "stack mac" config. My MAC will change after failover.
Support during stack formation, stack merge, and stack split
This section illustrates hitless stacking support during stack formation, stack merge, and stack split.
Runtime configuration mismatch
104 FastIron Ethernet Switch Stacking Configuration Guide
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