Deployment Guide

High Availability on Stacks
Stacks have master and standby management units analogous to Dell EMC Networking route processor modules (RPM).
The master unit synchronizes the running configuration and protocol states so that the system fails over in the event of a
hardware or software fault on the master unit. In such an event, or when the master unit is removed, the standby unit becomes
the stack manager and Dell EMC Networking OS elects a new standby unit. Dell EMC Networking OS resets the failed master
unit: after online, it becomes a member unit; the remaining members remain online.
Example of Stack Manager Redundancy
Management Access on Stacks
You can access the stack via the console port or VTY line.
● Console access — You may access the stack through the console port of the master unit (stack manager) only. Similar
to a standby RPM, the console port of the standby unit does not provide management capability; only a limited number of
commands are available. Member units provide a limited set of commands.
● Remote access — You may access the master unit and standby unit in a stack through the dedicated management
Ethernet interfaces with SNMP, SSH, or via Telnet.
Example of Accessing Non-Master Units on a Stack via the Console Port
-----------------CONSOLE ACCESS ON A STANDBY----------------------------
Dell(standby)#?
cd Change current directory
clear Reset functions
copy Copy from one file to another
delete Delete a file
dir List files on a filesystem
disable Turn off privileged commands
enable Turn on privileged commands
exit Exit from the EXEC
format Format a filesystem
fsck Filesystem check utility
pwd Display current working directory
rename Rename a file
reset Reset selected card
show Show running system information
ssh-peer-stack-unit Open a SSH connection to the peer stack-unit
start Start shell
telnet-peer-stack-unit Open a telnet connection to the peer stack-unit
terminal Set terminal line parameters
upload Upload file
Dell(standby)#
-----------------CONSOLE ACCESS ON A MEMBER----------------------------
Dell(stack-member-1)#?
reset-self Reset this unit alone
show Show running system information
You can connect two units with two or more stacking cables in case of a stacking port or cable failure. Removal of only one of
the cables does not trigger a reset.
Important Points to Remember
● You can stack up to six systems.
● You cannot stack one system with other system types.
● You cannot enable stacking and virtual link trunking (VLT) simultaneously on the device. To convert a stacked unit to VLT,
see Reconfiguring Stacked Switches as VLT.
● When using the 40G ports, you can configure a single port as a stack port; each 40G port is a stack-group.
● All stack units must have the same version of Dell EMC Networking OS.
Stacking
859