Dell S4820T Configuration Manual page 962

You can connect the units while they are powered down or up. Stacking ports are bi-directional.
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 Networking OS version.
If the stack is running Dell Networking OS version 8.3.12.0 and 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 Networking OS version 8.3.10.x, it is upgraded to use the same Dell
Networking OS version as the stack, rebooted, and joined the stack.
• If the new unit is running an Dell Networking OS version prior to 8.3.10.x , the unit is put into a card
problem state, Dell Networking OS is not upgraded, and a syslog message is raised. The unit must be
upgraded to Dell Networking OS version 8.3.12.0 before you can proceed.
Syslog messages are generated by the management unit:
• before the management unit downloads its Dell 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 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 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 an S4820T unit for stacking, use the following commands.
NOTE: After a port has been allocated for stacking, you can only use it for stacking. If stack-group 0
is allocated for stacking, you can use ports 0, 1, 2, and 3 for stacking but not for Ethernet anymore.
If only port 0 is used for stacking, ports 1, 2, and 3 are spare; they cannot be used for Ethernet.
NOTE: You can stack a maximum of two 10G stack ports.
NOTE: After a port is allocated for stacking, you can only use it for stacking. If stack-group 1 is
allocated for stacking, you can use ports 1, 2, 3, and 4 for stacking but not for Ethernet anymore. If
only port 1 is used for stacking, ports 2, 3, and 4 are spare; they cannot be used for Ethernet.
1. Assign a stack group for each unit.
CONFIGURATION mode
stack-unit id stack-group id
Begin with the first port on the management unit. Next, configure both ports on each subsequent
unit. Finally, return to the management unit and configure the last port.
The range is from 0 to 15.
2. Save the stacking configuration on the ports.
962
Stacking