Administration: Stack Management
Software Auto Synchronization in Stack
Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4 132
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Consistency of Stack Unit Modes in the Stack
All units in the stack must have the same stack unit mode.
When the stack is initialized, it runs a topology discovery algorithm that collects information 
on the units of the stack.
After a unit is selected to become the master, it can reject its neighbor’s request to join the 
stack if it has an inconsistent stack unit mode. When a unit is rejected because of its stack unit 
mode, it is logically shutdown (the ports cannot send/receive traffic) and all its LEDs (system, 
FAN, unit IDs, network ports and stack ports LEDs) are turned on. The information regarding 
the stack unit mode is displayed as a SYSLOG error in the master unit.
Note that the only way for the unit to recover from this state is by unplugging it from the 
electrical source and plugging it back in. This operation must be preformed when an affected 
unit is disconnected from the stack. After this operation, the affected unit mode can be 
changed to the current stack mode and the unit can be rejoined to the stack.
Stack Unit Type
If a unit of one type (GE/FE/XG) is removed from the stack and replaced with a unit of 
another type, the device attempts to apply the configuration of the previous unit to the new 
unit. This usually succeeds, but there are exceptions as described below:
Max number of IPv6 hosts 210 1776 210
Max. number of IPv6 routes 245 1792 245
Max. number of IPv6  
Multicast routes
118 900 118
Max. onlink IPv6 prefix 200 256 200
Max. MAC table aging 400 630 400
IPv6 manual tunnel/ 6to4 
tunnel/ ISATAP routing 
tunnel
Not supported Supported Not supported
Feature/Table Sx350X SG350XG/
SX350X
Hybrid Stack