Effects Of Replacing A Provisioned Switch In A Stack; Effects Of Removing A Provisioned Switch From A Stack; Stack Software Compatibility Recommendations; Stack Protocol Version Compatibility - Cisco Catalyst 2975 Software Configuration Manual

Chapter 6 Managing Switch Stacks

Effects of Replacing a Provisioned Switch in a Stack

When a provisioned switch in a switch stack fails, is removed from the stack, and is replaced with
another switch, the stack applies either the provisioned configuration or the default configuration to it.
The events that occur when the switch stack compares the provisioned configuration with the
provisioned switch are the same as those described in the
Stack" section on page

Effects of Removing a Provisioned Switch from a Stack

If you remove a provisioned switch from the switch stack, the configuration associated with the removed
stack member remains in the running configuration as provisioned information. To completely remove
the configuration, use the no switch stack-member-number provision global configuration command.

Stack Software Compatibility Recommendations

All stack members must run the same Cisco IOS software version to ensure compatibility in the stack
protocol version among the members.

Stack Protocol Version Compatibility

The stack protocol version has a major version number and a minor version number (for example 1.4,
where 1 is the major version number and 4 is the minor version number).
Switches with the same Cisco IOS software version have the same stack protocol version. All features
function properly across the stack. These switches with the same software version as the master
immediately join the stack.
If an incompatibility exists, a system message describes the cause of the incompatibility on the specific
stack members. The master sends the message to all members.
For more information, see the
page 6-9

Major Version Number Incompatibility Among Switches

Switches with different Cisco IOS software versions likely have different stack protocol versions.
Switches with different major version numbers are incompatible and cannot exist in the same stack.

Minor Version Number Incompatibility Among Switches

Switches with the same major version number but with a different minor version number as the master
are considered partially compatible. When connected to a stack, a partially compatible switch enters
version-mismatch mode and cannot join the stack as a fully functioning member. The software detects
the mismatched software and tries to upgrade (or downgrade) the switch in version-mismatch mode with
the stack image or with a tar file image from the stack flash memory. The software uses the automatic
upgrade (auto-upgrade) and the automatic advise (auto-advise) features.
The port LEDs on switches in version-mismatch mode will also stay off. Pressing the Mode button does
not change the LED mode.
OL-19720-02
6-7.
"Major Version Number Incompatibility Among Switches" procedure on
and the "Minor Version Number Incompatibility Among Switches" procedure on page
"Effects of Adding a Provisioned Switch to a
Catalyst 2975 Switch Software Configuration Guide
Understanding Stacks
6-9.
6-9