Reference Guide

880 | Stacking
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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 traffic 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 S5000 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 S5000 switches 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 (Figure 48-19).
To re-enable a downed stacking port, power cycle the stacked switch on which the port is installed.
Figure 48-19. Recovering from a Stack-Link Flapping Error
--------------------------------------MANAGMENT UNIT-----------------------------------------
Error: Stack Port 48 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 52 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 52 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.
----------------------------------------MEMBER 2---------------------------------------------
Error: Stack Port 52 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.