Reference Guide

Configuring an S5000 Switch Stack
To configure and bring up a switch stack, follow these steps.
1. Power down the switches stack and attach port cables to connect the ports between pairs of
switches. Connect ports with the same speed on each pair of stacked switches.
2. Power up each stack unit.
3. Configure the stacking ports on each switch, including unit number and priority.
4. Save the stacking configuration to the startup configuration and reload each stacked switch, one
after another.
Stack and Cable Requirements
Before you cable a stack of S5000 switches, review the following requirements.
• You can connect up to a maximum of six S5000s in a single stack.
– Use SFP+/QSFP+ transceivers and SFP+/QSFP+ cables or direct attach cables (DACs) to connect
stacking ports. Attach cables only when stack units are powered down. Use SFP+ cables to
connect 10GbE ports; use QSFP+ cables to connect 40GbE ports. For more information, refer to
the Dell Networking S5000 Installation Guide.
• Stacking is supported only with other S5000 switches. You cannot stack an S5000 switch with other
S-Series switches.
• Only daisy-chain or ring topologies are supported; star and full mesh topologies are not supported.
• Stacking is not supported on Fibre Channel ports. If you install a Fibre Channel module in the switch,
the following warning message displays when you configure a stack group on Ethernet ports: %
Error: Cannot configure stack group when FC module is enabled.
• Although you can have 10 GbE and 40 GbE links in an S5000 stack, connect ports with the same
speed on each pair of stacked switches: cable 10 GbE to 10 GbE ports or 40 GbE to 40 GbE ports.
– Stacking is not supported on 40 GbE ports operating in 4x10G (quad) mode. To convert a fixed 40
GbE port on the front panel from 4x10GbE mode of operation to 40 GbE mode, refer to
Converting Four 10 GbE Ports to 40 GbE Ports for Stacking.
• If you use three or more units in an S5000 stack, you can connect up to eight 10 GbE or two 40 GbE
links between peer switches. If you use only two units in an S5000 stack, you can connect up to four
40 GbE links between peer switches.
• All stacked S5000 switches must run the same Dell Networking OS version. The minimum Dell
Networking OS version required is 9.1(1.0). To check the Dell Networking OS version that a switch is
running, power on the switch and enter the show version command. To download a Dell
Networking OS version, go to http://support.dell.com.
• Stacking is not supported on switches enabled for virtual link trunking (VLT). To convert a stack unit to
VLT operation, refer to Reconfiguring Stacked Switches as VLT.
NOTE: Enable stacking on an S5000 switch by specifying one or more stack groups. A stack group
can consist of four 10 GbE ports or one 40 GbE port. If you enable stacking on a group of four 10
GbE ports, all ports in the stack group are enabled for stacking. To maximize throughput, Dell
recommends using all four 10 GbE ports in the group for stacking. You cannot use 10 GbE ports in a
stack group which are enabled for stacking as data ports.
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Stacking