Deployment Guide

If the stacked switches all reboot at approximately the same time, the Aggregator with the highest MAC address is automatically elected as
the master switch. The Aggregator with the next highest MAC address is elected as the standby master.
NOTE: You can ensure that a stacked switch becomes the master by rebooting the switch rst, and waiting for it to come up
before rebooting the second switch in the stack. It is recommended to have the boot image for the stack units via boot from
ash.
The Status LED on the Aggregator that is elected as the master switch is blue. Perform VLAN and other software conguration for the
stack by connecting to the console port on the master unit. To determine which switch is the stack master, enter the show system
command at the terminal.
To remove an Aggregator from the stack, enter the stack-unit 0 iom-mode standalone command in Global conguration mode,
save the conguration and reload the Aggregator for the change to take eect.
In stack mode, all VLAN membership are removed and the port is assigned only to the default VLAN1. You must congure additional VLAN
membership, as required.
Adding a Stack Unit
You can add a new unit to an existing stack both when the unit has no stacking ports (stack groups) congured and when the unit already
has stacking ports congured. If the units to be added to the stack have been previously used, they are assigned the smallest available unit
ID in the stack.
To add a standalone Aggregator to a stack, follow these steps:
1 Power on the switch.
2 Attach SFP+ or direct attach cables to connect 10G ports on the switch to one or more switches in the stack.
3 Log on to the CLI and enter global conguration mode.
Login: username
Password: *****
Dell> enable
Dell# congure
4 Congure the Aggregator to operate in stacking mode.
CONFIGURATION mode
stack-unit 0 iom-mode
stack
5 Reload the switch. Dell Operating System 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.
EXEC Privilege mode
reload
If an Aggregator is already congured to operate in stacking mode, simply attach SFP+ or direct attach cables to connect 10G ports on the
base module of each stacked Aggregator. The new unit synchronizes its running and startup congurations with the stack.
Dell Networking OS Behavior: When you add a new Aggregator to a stack:
• If the new unit has been congured 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.
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Stacking