Users Guide
The following syslog messages are generated when a member unit fails:
Dell#May 31 01:46:17: %STKUNIT3-M:CP %IPC-2-STATUS: target stack unit 4 not responding
May 31 01:46:17: %STKUNIT3-M:CP %CHMGR-2-STACKUNIT_DOWN: Major alarm: Stack unit 4 down - IPC
timeout
Dell#May 31 01:46:17: %STKUNIT3-M:CP %IFMGR-1-DEL_PORT: Removed port: Te 4/1-32,41-48, Fo 4/
49,53
Dell#May 31 01:46:18: %STKUNIT5-S:CP %IFMGR-1-DEL_PORT: Removed port: Te 4/1-32,41-48, Fo 4/
49,53
Unplugged Stacking Cable
• Problem: A stacking cable is unplugged from a member switch. The stack loses half of its bandwidth from the disconnected switch.
• Resolution: Intra-stack trac is re-routed on a another link using the redundant stacking port on the switch. A recalculation of control
plane and data plane connections is performed.
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 trac on the new master switch is uninterrupted. Protocol trac is managed by the
control plane.
3 A member switch is elected as the new standby. Data trac 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.
Stacking
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