Reference Guide

Stacking | 881
Master Switch Recovers from Failure
Problem: The master switch recovers from a failure after a reboot and rejoins the stack:
• As a member unit if there is already a standby
• As a standby if there is no standby in the stack
Protocol and control plane recovery requires time before the switch is fully online.
Resolution: When the entire stack is reloaded, the recovered master switch becomes the master unit of the
stack.
Stack Unit in Card-Problem State Due to Incorrect Dell networking OS Version
Problem: A stack unit enters a Card-Problem state because the switch has a different Dell networking OS
version than the master unit (Figure 48-20). The switch does not come online as a stack unit.
Resolution: The version mismatch case is taken cared of by firmware synchronization, which
automatically upgrades the unit to the required Dell networking OS version. You do not have to manually
upgrade the unit.
To verify that the problem has been resolved and the stacked switch is back online, use the
show system brief
command (Figure 48-21).