Deployment Guide

Stacking Installation Tasks
The following are the stacking installation tasks.
● Create a Stack
● Add Units to an Existing Stack
● Split a Stack
Create a Stack
No configuration is allowed on front end ports used for stacking. Stacking can be made between 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 1.
A maximum of six 40G stack links can be made between two units in a stack. The front end ports are divided into 32 stack
groups, each with 40G of bandwidth.
The front end ports accommodate QSFP+.
● Ports are divided into 32 stack-groups (0 to 31) as shown in the following example.
○ stack-group 0 to 31 corresponds to 32 40 gig ports
Figure 121. Stack-Group Assignments
You can connect the units while they are powered down or up. Stacking ports are bidirectional.
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 EMC Networking OS version. If the stack is running Dell EMC Networking
OS versionand 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 EMC Networking OS version it is upgraded to use the same Dell EMC Networking OS version as the
stack, rebooted, and joined the stack.
● If the new unit is running an Dell EMC Networking OS version prior to, the unit is put into a card problem state, Dell EMC
Networking OS is not upgraded, and a syslog message is raised. The unit must be upgraded to Dell EMC Networking OS
version before you can proceed.
Syslog messages are generated by the management unit:
● before the management unit downloads its Dell EMC Networking OS version or later to the new unit. The syslog includes the
unit number, previous version, and version being downloaded.
● when the firmware synchronization is complete.
● if the system check fails, a message such as a hardware incompatibility message or incompatible uboot version is generated.
If the unit is placed in a card problem state, the management unit also generates an SNMP trap.
● if the software version of the new unit predates Dell EMC Networking OS version , the management unit puts the new
unit into a card problem state and generates a syslog that identifies the unit, its Dell EMC Networking OS version, and its
incompatibility for firmware synchronization.
NOTE:
Any scripts used to streamline the stacking configuration process must be updated to reflect the Command Mode
change from EXEC to CONFIGURATION to allow the scripts to work correctly.
860 Stacking