Converting 4x10GbE Ports to 40GbE for Stacking

Stacking is supported only on 40GbE links by connecting 40GbE ports on the base module or a 2-Port
QSFP+ module.
However, on a 2-Port 40GbE QSFP+ module, the ports operate by default in 4x10GbE (quad) mode with
breakout cables as eight 10GbE ports.
Change a port from 4x10GbE to 40GbE mode of operation for stacking.
no stack-unit port portmode quad
After you convert the 4x10GbE ports to 40GbE, you must save the configuration and reload the stack
for the change to take effect.
•stack-unit unit-number is the unit ID number in the stack unit. The valid range is from 0 to
5.
•port port-number specifies the port number of the QSFP+ port to be converted to 40GbE
mode. The valid values are: base-module ports: 33 or 37; slot 0: 41 or 45; slot 1: 49 or 53. As
shown below, portmode quad identifies the port as a split 10GbE SFP+ port.
Example of the no stack-unit port portmode quad Command
Dell(conf)# no stack-unit unit-number port port-number portmode quad
To display the stack-unit number, use the show system brief command.

Removing a Port from the Stacking Mode

To remove a 40GbE port from the stack, use the no form of the stack-unit unit-number stack-
group number command.
After entering the command, save the configuration and reload the stack for the change to take effect.
Remove a stacked port from a stack.
CONFIGURATION mode
no stack-unit unit-number stack-group group end write memory reload
When the reload completes, the port comes up in 40GbE mode if it is on the base module and in
4x10GbE (quad) mode if the port is on a FlexIO module, such as a 2-Port 40GbE QSFP+ module.
Removing a Switch from a Stack
To remove a switch from a stack, disconnect the stacking cables from the unit either when the unit is
powered on or off and is online or offline.
After you remove all 40GbE ports from a stack (Removing a Port from the Stacking Mode), the switch
functions in standalone mode but retains the running and startup configuration that was last
synchronized by the master switch while it operated as a stack unit.
If you remove a unit from the middle of a stack, the stack is split into multiple parts. Each split stack forms
a new stack according to MAC addresses or assigned priorities, as described in Configuring and
Configuring and Bringing Up a Stack and Assigning a Priority to Stacked Switches.
894 Stacking