Users Guide

Dell Networking OS automatically assigns a number to the new unit and adds it as member switch in the stack. The new unit
synchronizes its running and startup congurations with the stack.
Dell Networking OS Behavior: When you add a switch to a stack
• If you congure the new unit with a stack number that is already assigned to a stack member, the stack avoids a numbering
conict by assigning the new switch the rst available stack number.
• If the stack has been provisioned for the stack number that is assigned to the new unit, the pre-congured provisioning must
match the switch type. If there is a conict between the provisioned switch type and the new unit, a mismatch error message is
displayed.
Merge Two S-Series Stacks
You may merge two stacks while they are powered and online.
To merge two stacks, connect one stack to the other using user port cables from the front end user port.
• Dell Networking OS selects a master stack manager from the two existing managers based on the priority of the stack.
• Dell Networking OS resets all the units in the losing stack; they all become stack members.
• If there is no unit numbering conict, the stack members retain their previous unit numbers. Otherwise, the stack manager
assigns new unit numbers, based on the order that they come online.
• The stack manager overwrites the startup and running cong on the losing stack members with its own to synchronize the
conguration on the new stack members.
Split an S-Series Stack
To split a stack, unplug the desired stacking cables.
You may do this at any time, whether the stack is powered or unpowered, and the units are online or oine. Each portion of the split
stack retains the startup and running conguration of the original stack.
For a parent stack that is split into two child stacks, A and B, each with multiple units:
• If one of the new stacks receives the master and the standby management units, it is unaected by the split.
• If one of the new stacks receives only the master unit, that unit remains the stack manager, and Dell Networking OS elects a
new standby management unit.
• If one of the new stacks receives only the standby unit, it becomes the master unit of the new stack, and Dell Networking OS
elects a new standby unit.
• If one of the new stacks receives neither the master nor the standby management unit, the stack is reset so that a new election
can take place.
Stack Unit and Stack Group Numbering
Enable ports for stacking by specifying a stack-unit number and stack-group number (the stack-unit number stack-group
number command).
• Stack-unit numbers: By default, each switch in Standalone mode is numbered stack-unit 0. Stack-unit numbers are assigned to
member switches when a stack comes up. To pre-congure the units which are the master and standby when the stack boots
up, you can assign unit numbers using the stack-unit renumber command.
• Stack-group numbers: Stacking ports are divided into 16 stack-groups (from 0 to 15), as shown in the following illustration. Each
set of four 10 GbE ports on an Ethernet module or each xed 40 GbE port on the front panel correspond to a stack group. Each
stack group has 40 GbE of bandwidth.
Usage Notes:
• Stacking is not supported on Fibre Channel ports.
• If you use a Fibre Channel module in an S5000 switch, stacking is not supported on Ethernet ports.
• If you use three or more S5000 units in a stack, you can connect up to a maximum of eight 10 GbE ports or two 40 GbE ports in
links between peer switches.
• If you use only two S5000 units in a stack, you can connect up to four 40 GbE ports in links between the two switches.
Stack groups 0 through 11 consist of four 10 GbE ports; stack groups from 12 to 15 consist of one 40G port as follows:
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Stacking