Master Switch Fails; Stack-Link Flapping Error; Master Switch Recovers From Failure - Dell PowerEdge M IO Aggregator Command Reference Manual

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 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.
Figure 17-28. Recovering from a Stack-Link Flapping Error
--------------------------------------MANAGMENT UNIT-----------------------------------------
Error:
Error: Please check the stack cable/module and power-cycle the stack.
10:55:20: %STKUNIT1-M:CP
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.
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.
218 | Stacking
Stack Port 49 has flapped 5 times within 10
%KERN-2-INT:
(Figure 17-28).
seconds.Shutting down this stack port now.
Error: Stack Port 50 has flapped 5 times within 10