Users Guide
• You cannot enable stacking and virtual link trunking (VLT) simultaneously on the device. To convert a stacked unit to VLT, refer to
Reconguring Stacked Switches as VLT.
• Data ports are congured as stacking ports in predened groups of four 10G ports called stack-groups. When using the 40G
ports, you can congure a single port as a stack port; each 40G port is a stack-group.
• All the ports in a stack-group are placed in stacking mode. Unused ports in that group cannot be used as data ports.
• Stacking on the device is accomplished through front-end user ports on the chassis.
• All stack units must have the same version of Dell Networking OS.
S-Series Stacking Installation Tasks
The following are the S-Series stacking installation tasks.
• Create an S-Series Stack
• Add Units to an Existing S-Series Stack
• Split an S-Series Stack
Create an S-Series Stack
Stacking is enabled on the device using the front end ports.
No conguration is allowed on front end ports used for stacking. Stacking can be made between 10G ports of two units or 40G ports
of two units. The stack links between the two units are grouped into a single LAG.
Stack Group/Port Numbers
By default, each unit in Standalone mode is numbered stack-unit 0.
A maximum of eight 10G stack links or two 40G stack links can be made between two units in a stack. The front end ports are
divided into 16 stack groups, each with 40G of bandwidth. Stack groups 0 through 11 correspond to 10G stack groups with four ports
each. Stack groups 12 to 15 are one 40G port each.
The front end ports accommodate SFP, SFP+ and QSFP+.
• Ports are divided into 16 stack-groups (0 to 15) as shown in the following example. The stack groups must be of a single speed -
either all 10G or all 40G.
– stack-group 0 corresponds to ports 0-3, stack-group 1 corresponds to ports 4-7, so on through stack-group 11.
– stack-group 12 corresponds to the 40G port 48, stack-group 13 corresponds to port 52, so on through stack group 15.
Figure 118. Stack-Group Assignments
You can connect the units while they are powered down or up. Stacking ports are bi-directional.
When a unit is added to a stack, the management unit performs a system check on the new unit to ensure the hardware type is
compatible. A similar check is performed on the Dell Networking OS version. If the stack is running Dell Networking OS version
8.3.12.0 and the new unit is running an earlier software version, the new unit is put into a card problem state.
• If the unit is running Dell Networking OS version 8.3.10.x, it is upgraded to use the same Dell Networking OS version as the stack,
rebooted, and joined the stack.
Stacking
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