Concept Guide

Create a Stack
Stacking is enabled on the device using the front end ports.
No configuration 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 1.
A maximum of eight 10G stack links or four 40G stack links can be made between two units in a stack. The front end ports are
divided into 18 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 17 are one 40G port each.
The front end ports accommodate QSFP+.
● Ports are divided into 18 stack-groups (0 to 17) 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 1-4, stack-group 1 corresponds to ports 5-8, so on through stack-group 11.
○ stack-group 12 corresponds to the 40G port 49, stack-group 13 corresponds to port 50, so on through stack group 17.
Figure 127. Stack-Group Assignments
1.
Stack-group 0 (Ports 1, 2, 3, and 4) 2. Stack-group 1 (Ports 5, 6, 7, and 8)
3. Stack-group 2 (Ports 9, 10, 11, and 12) 4. Stack-group 3 (Ports 13, 14, 15, and 16)
5. Stack-group 12 (Port 49) 6. Stack-group 14 (Port 51)
7. Stack-group 16 (Port 53) 8. Stack-group 17 (Port 54)
9. Stack-group 15 (Port 52) 10. Stack-group 13 (Port 50)
You can connect the units while they are powered down or up. Stacking ports are bi-directional.
Syslog messages are generated by the management unit:
● before the management unit downloads its Dell EMC Networking OS version 8.3.12.0 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 8.3.12.0 , 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:
You must enter the stack-unit stack-unit stack-group stack-group command when adding units to
a stack to ensure the units are assigned to the correct groups.
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.
Enabling Front End Port Stacking
To enable the front ports on a unit for stacking, use the following commands.
NOTE: You can stack a maximum of eight 10G stack ports.
906 Stacking