Brocade FastIron Ethernet Switch Stacking Configuration Guide - Manual (Page 91)

Advanced feature privileges
Advanced feature privileges must be enabled to run advanced features such as BGP. Both active and
standby units must be enabled for advanced features for these features to operate across the stack. A
unit that is not enabled for these features is put into a non-operational state.
If the active controller is not enabled for advanced features, these features will not operate on the stack.
Traditional stack technology requires that all stack units run the same version of the software image. In
cases where the software version differs, there are two levels of mismatch, major and minor.
Major mismatch for stack units
A major mismatch indicates an Interprocessor Communications (IPC)-related data structure change, or
an election algorithm change, or that a version of the software that does not support stacking is installed
on a unit. This can happen when the software undergoes a major change (such as a change from
05.0.00 to 05.1.00). When a major mismatch occurs, the system logs and prints a message similar to
the following.
Warning! Recv 424 IPC in 1m from 0000.001b.a900 e1/1/25: wrong version 5 !=6. Please
make sure all units run the same image.
In a major mismatch, the stack cannot be built and will not operate. You must download the correct
version of the software to the mismatched units individually.
Minor mismatch for stack units
With a minor mismatch, an operating stack can still exist, but traffic is dropped from all ports except for
the stacking ports for units with the mismatched software. You can download the correct image to the
mismatched devices from the active controller. A minor software mismatch means that there is no IPC
or election algorithm change, but there is a release version disparity. Minor software mismatches can
happen with patch release upgrades. The system logs and prints a message similar to the following.
Warning! put stack unit 2 to non-operational reason=image mismatch
The show stack command displays output similar to the following.
device# show stack
alone: standalone, D: dynamic config, S: static config
ID Type Role MAC Address Pri State Comment
1 S FCX624 active 0000.00eb.a900 128 local Ready
2 S FCX648 standby 0000.004f.4243 0 remote NON-OP: image mismatch
3 S FCX624 member 0000.0001.0100 0 remote Ready
If the configuration of a stack unit does not match the configuration of the active controller, the stack unit
will not function. In this example, unit 2 is non-operational due to an image mismatch. To correct this
situation, use the copy flash flash command. Refer to “Copying the flash image to a stack unit from the
active controller.”
Configuration mismatch for stack units
Generally, when a stack unit is added to or removed from the stack, its static configuration is not
overwritten by the active controller. On the other hand, the active controller deletes the dynamic
configuration for a unit if it leaves.
A configuration mismatch occurs when the base module configuration for a replacement stack unit does
not match the runtime configuration on the active controller. If the configuration on the active controller
is static, it cannot be overwritten by the new configuration, and a configuration mismatch occurs.
Advanced feature privileges
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