User guide

Roles Within the Stack Managing OmniSwitch 6855 Series Stacks
page 7-14 OmniSwitch 6855 Series Hardware Users Guide January 2013
To avoid a pass-through condition following a reboot, make sure that all saved slot values for the stack are
unique. Use the stack set slot command. For example, change the saved slot value for the idle switch in
slot 3 from 2 to 3:
-> stack set slot 3 saved-slot 2
Use the show stack topology command to verify the change:
-> show stack topology
Link A Link A Link B Link B
NI Role State Saved Link A Remote Remote Link B Remote Remote
Slot State NI Port State NI Port
----+-----------+--------+------+-------+-------+-------+-------+-------+-------
1 PRIMARY RUNNING 1 UP 3 StackA UP 2 StackA
2 SECONDARY RUNNING 2 UP 1 StackB UP 3 StackB
3 IDLE RUNNING 3 UP 1 StackA UP 2 StackB
Recovering from Pass-Through Mode (Duplicate Slot Numbers)
The first step in recovering from pass-through is to determine which modules are currently operating in
pass-through, as well as the reason for the pass-through state. To view this information, use the
show stack topology command. For example:
-> show stack topology
Link A Link A Link B Link B
NI Role State Saved Link A Remote Remote Link B Remote Remote
Slot State NI Port State NI Port
----+-----------+--------+------+-------+-------+-------+-------+-------+-------
1 PRIMARY RUNNING 1 UP 1001 StackA UP 2 StackA
2 SECONDARY RUNNING 2 UP 1 StackB UP 1001 StackB
1001 PASS-THRU DUP-SLOT 2 UP 1 StackA UP 2 StackB
Switches operating in pass-through mode are given distinct slot numbers. These slot numbers are not
related to their position in the stack. Instead, they are assigned the prefix “100,” followed by the numeri-
cal order in which they were forced into pass-through (1001–1008).
Note. For pass-through elements 1001 through 1008, the slot indicator LED on the chassis front panel
blinks 1 through 8, respectively. For example, if a module enters pass-through and has the slot number
1004, the LED for the module blinks the number 4. For more information on the slot indicator LED, refer
to “Status LEDs” on page 2-21.
In the example above, the switch with the NI (i.e., slot) number 1001 is operating in pass-through. Note
that the role assignment is PASS-THRU; also, the state displays DUP-SLOT, or duplicate slot number.
This can be further verified by looking down the saved slot column in the table. Note that slot 2, operating
in the secondary management role, has a saved slot value of 2. Slot 1001, operating in pass-through, also
has a saved slot value of 2.