Managing OmniSwitch 6855 Series Stacks
Stack Cabling
OmniSwitch 6855 Series Hardware Users Guide
September 2011
page 7-19
Redundant stacking cables provide a form of
dual
redundancy. As shown in the figure above, the redun-
dant cable allows traffic to flow in the event of a stacking link failure. The redundant cable also provides
failover if a
switch
goes down within the stack. Traffic continues to flow between the modules that remain
operational, as shown in the diagram below:
Stacking Cable Redundancy: Recovery Following a Switch Failure within the Stack
Checking Redundant Stacking Cable Status
To check whether a redundant stacking cable connection exists between the top-most and bottom-most
switches in the stack, use the
show stack status
command. For example:
-> show stack status
Redundant cable status : present
Tokens used : 12
Tokens available : 20
In this example, a redundant stacking cable connection is present between the top-most and bottom-most
switches in the stack.
Slot 1
Slot 2
Slot 3
Slot 4
Chassis Front
Stacking Cables
Data enters slot 1 through the Ethernet port. The data
traverses slot 2 via the stacking cables and exits slot 3
through one of its Ethernet ports.
1
2
The slot 2 switch goes down unexpectedly. Data can no
longer move through slot 2.
However, because there is a redundant connection (the
cable between slot 1 and slot 4), data immediately
traverses slot 4 and then exits slot 3 to its destination.
Slot 1
Slot 2
Slot 3
Slot 4
