Reference Guide

Stacking | 921
Figure 46-7. S4810 Stack-group assignments
Figure 46-8. S4820T Stack-Group Assignment
You can connect the units while they are powered down or up. Stacking ports are bi-directional.
With FTOS 8.3.12.0, 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 FTOS version. If
the stack is running 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 version 8.3.10.x, it is upgraded to use the same FTOS version as the stack,
rebooted and join the stack.
• If the new unit is running an FTOS version prior to 8.3.10.x, the unit is put into a card problem state,
FTOS is not upgraded, and a syslog message is raised. The unit must be upgraded to FTOS 8.3.12.0
before you can proceed.
Syslog messages are generated by the management unit:
• before the management unit downloads its FTOS version (FTOS 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.
Stack Group 0
Stack Group 1
Stack Group 2
Stack Group 3
Stack Group 11
Stack Group 10
SG-13 SG-15
SG-12 SG-14