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2. The standby switch takes the master role. Data traffic on the new master switch is uninterrupted. Protocol traffic is
managed by the control plane.
3. A member switch is elected as the new standby. Data traffic on the new standby is uninterrupted. The control plane
prepares for operation in Warm Standby mode.
Stack-Link Flapping Error
Problem/Resolution: Stacked Aggregators monitor their own stack ports and disable any stack port that flaps five times
within 10 seconds. If the stacking ports that flap are on the master or standby, KERN-2-INT error messages note the units.
To re-enable a downed stacking port, power cycle the stacked switch on which the port is installed.
The following is an example of the stack-link flapping error message.
--------------------------------------MANAGMENT
UNIT-----------------------------------------
Error: Stack Port 49 has flapped 5 times within 10 seconds.Shutting down this stack port now.
Error: Please check the stack cable/module and power-cycle the stack.
10:55:20: %STKUNIT1-M:CP %KERN-2-INT: Error: Stack Port 50 has flapped 5 times within 10
seconds.Shutting down this stack port now.
10:55:20: %STKUNIT1-M:CP %KERN-2-INT: Error: Please check the stack cable/module and
power-cycle the stack.
---------------------------------------STANDBY
UNIT------------------------------------------
10:55:18: %STKUNIT1-M:CP %KERN-2-INT: Error: Stack Port 50 has flapped 5 times within 10
seonds.Shutting down this stack port now.
10:55:18: %STKUNIT1-M:CP %KERN-2-INT: Error: Please check the stack cable/module
and power-cycle the stack.
Master Switch Recovers from Failure
● Problem: The master switch recovers from a failure after a reboot and rejoins the stack as the standby unit or member unit.
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. The switch does not come online as a stack unit.
● Resolution: To restore a stack unit with an incorrect Dell Networking OS version as a member unit, disconnect the stacking
cables on the switch and install the correct Dell Networking OS version. Then add the switch to the stack as described in
Adding a Stack Unit. To verify that the problem has been resolved and the stacked switch is back online, use the show
system brief command.
Dell#show system brief
Stack MAC : 00:1e:c9:f1:00:9b
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
--------------------------------------------------------------------------
0 Management online PE-FN-410S-IOA PE-FN-410S-IOA 1-0(0-1864) 12
1 Standby card problem PE-FN-410S-IOA unknown 12
2 Member not present
3 Member not present
4 Member not present
5 Member not present
Card Problem — Resolved
Dell#show system brief
Stack MAC : 00:1e:c9:f1:04:82
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
----------------------------------------------------------------------
Stacking
759