Reference Guide

Master Switch Fails
• Problem: The master switch fails due to a hardware fault, software crash, or power loss.
• Resolution: A failover procedure begins:
1. Keep-alive messages from the Aggregator master switch time out after 60 seconds and the switch is removed from the stack.
2. The standby switch takes the master role. Data trac on the new master switch is uninterrupted. Protocol trac is managed
by the control plane.
3. A member switch is elected as the new standby. Data trac 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 aps ve times within 10
seconds. If the stacking ports that ap 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 apping 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 dierent 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
Stacking
183