Reference Guide

Stacking | 865
2. Power up each S5000 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 S5000 switch, one
after another.
Stacking and Cabling 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. Refer to the S5000 Installation Guide for
detailed information.
• 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 a Fibre Channel module is installed in the switch,
the following warning message is displayed when you configure a stack group on Ethernet ports:
% Error: Cannot configure stack group when FC module is enabled.
• Although you can have 10GbE and 40GbE links in an S5000 stack, you must connect ports with the
same speed on each pair of stacked switches: cable 10GbE to 10GbE ports or 40GbE to 40GbE ports.
Stacking is not supported on 40GbE ports operating in 4x10G (quad) mode. To convert a fixed 40GbE
port on the front panel from 4x10GbE mode of operation to 40GbE mode, refer to Converting
4x10GbE Ports to 40GbE for Stacking.
• If you use three or more units in an S5000 stack, you can connect up to eight 10GbE or two 40GbE
links between peer switches. If you use only two units in an S5000 stack, you can connect up to four
40GbE links between peer switches.
• All stacked S5000 switches must run the same FTOS version. The minimum FTOS version required is
9.0(1.3). To check the FTOS version that a switch is running, power on the switch and enter the
show
version
command. To download an FTOS 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, see Reconfiguring Stacked Switches as VLT.
Important: You enable stacking on an S5000 switch by specifying one or more stack groups. As shown in
Table 47-1, a stack group can consist of four 10GbE ports or one 40GbE port. If you enable stacking on a
group of four 10GbE ports, all ports in the stack group are enabled for stacking. Dell recommends that you
use all four 10GbE ports in the group for stacking to maximize throughput. 10GbE ports in a stack group
which is enabled for stacking cannot be used as data ports.
Cabling Stacked Switches
Before you attach cables to set up a stack of S5000 switches, ensure that the FTOS version running on each
unit is the same (
show version command) and that all switches are powered down. Review the cabling
requirements in Stacking and Cabling Requirements.