Hardware Compatibility And Sdm Mismatch Mode In Switch Stacks; Switch Stack Software Compatibility Recommendations; Stack Protocol Version Compatibility - Cisco 3750G - Catalyst Integrated Wireless LAN Controller Configuration Manual

Understanding Switch Stacks

Hardware Compatibility and SDM Mismatch Mode in Switch Stacks

The Catalyst 3750-12S switch supports desktop and aggregator Switch Database Management (SDM)
templates. All other Catalyst 3750 switches support only the desktop SDM templates.
All stack members use the SDM template configured on the stack master. If the stack master is using an
aggregator template, only Catalyst 3750-12S switches can be stack members. All other switches
attempting to join this switch stack enter SDM-mismatch mode. These switches can join the stack only
when the stack master is running a desktop SDM template.
We recommend that your stack master use an aggregator template only if you plan to create a switch
stack of Catalyst 3750-12S switches. If you plan to have a switch stack with different Catalyst 3750
switch models, configure the stack master to use one of the desktop templates.
Note Version-mismatch (VM) mode has priority over SDM-mismatch mode. If a VM-mode condition and an
SDM-mismatch mode exist, the switch stack attempts to resolve the VM-mode condition first.
You can use the show switch privileged EXEC command to see if any stack members are in
SDM-mismatch mode.
For more information about SDM templates and SDM-mismatch mode, see
SDM Templates."

Switch Stack Software Compatibility Recommendations

To ensure complete compatibility between stack members, use the information in this section and in the
"Hardware Compatibility and SDM Mismatch Mode in Switch Stacks" section on page
All stack members must run the same Cisco IOS software version to ensure compatibility between stack
members. This helps ensure full compatibility in the stack protocol version among the stack members.
For example, all stack members should have the IP services image Cisco IOS Release 12.1(14)EA1
installed. For more information, see the

Stack Protocol Version Compatibility

Each software image includes a stack protocol version. 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). Both version numbers determine the level of compatibility among the stack
members. You can display the stack protocol version by using the show platform stack-manager all
privileged EXEC command.
Switches with the same Cisco IOS software version have the same stack protocol version. Such switches
are fully compatible, and all features function properly across the switch stack. Switches with the same
Cisco IOS software version as the stack master immediately join the switch stack.
If an incompatibility exists, the fully functional stack members generate a system message that describes
the cause of the incompatibility on the specific stack members. The stack master sends the message to
all stack members. For more information, see the
Switches" procedure on page 5-11
procedure on page
Catalyst 3750 Switch Software Configuration Guide
5-10
"Stack Protocol Version Compatibility" section on page
and the "Minor Version Number Incompatibility Among Switches"
5-11.
Chapter 5
"Major Version Number Incompatibility Among
Managing Switch Stacks
Chapter 8, "Configuring
5-10.
5-10.
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