Administration: Stack Management
Stack Unit Mode
Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version) 73
5
Changing the Stack Unit Mode
Change the stack unit mode of a device to remove it from a stack (by changing its
stack unit mode to Standalone), or when configuring it to become part of a stack
(by changing its stack unit mode to Native Stacking, Basic Hybrid Stacking or
Advanced Hybrid Stacking).
The following sections describe the system mode and configuration of the
devices after reboot when the stack unit mode is changed.

System Mode (500 Devices) After Reboot

When the stack mode of a device is changed, the system mode of the device may
be changed after reboot:
Sx500 devices—The system mode (Layer 2 or Layer 3) of the backup and
slave Sx500 units is taken from the master-enabled unit. If the system mode
is not specifically set before reboot, it is Layer 2 after reboot (this is the
default). If you want the device to be in Layer 3 mode after reboot, this must
be specifically set before reboot.
SG500X/ESW2-550X devices—When the device is in Standalone or
Native Stacking mode, its system mode is always Layer 2 and 3. When the
device is in Basic or Advanced Hybrid mode, it behaves as described
above for Sx500 devices. When the device is in Advanced Hybrid XG mode,
its system mode is always Layer 2 and 3.
SG500XG devices—Always Layer 2 and Layer 3.

Configuration After Reboot

When you change the stack mode of a device and reboot the device, the Startup
Configuration file is usually removed because it may contain configuration
information that is not applicable to the new mode.
It is retained after bootup in the following cases:
SG500X/ESW2-550X devices:
-Standalone to Native Stacking—Retained only when the unit is forced
to become the master with unit ID = 1
-Basic Hybrid to Advanced Hybrid—Retained only when the unit is
forced to become the master with unit ID = 1
-Basic Hybrid to Advanced Hybrid XG—Retained only when the unit is
forced to become the master with unit ID = 1