Identifying Loopback Problems - Cisco 3032 Software Configuration Manual

Troubleshooting Stacks

Identifying Loopback Problems

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Software Loopback
In a stack with three members, stack cables connect all the members.
Switch# show switch stack-ports summary
Switch#/
Port#
--------
1/1
1/2
2/1
2/2
3/1
3/2
If you disconnect the stack cable from Port 1 on Switch 1, these messages appear:
01:09:55: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 3 has changed to state DOWN
01:09:56: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 1 has changed to state DOWN
Switch# show switch stack-ports summary
Switch#/
Port#
--------
1/1
1/2
2/1
2/2
3/1
3/2
If you disconnect the stack cable from Port 2 on Switch 1, the stack splits.
Switch 2 and Switch 3 are now in a two-member stack connected through stack cables.
Switch# show sw stack-ports summary
Switch#/
Port#
--------
2/1
2/2
3/1
3/2
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
5-30
Software Loopback, page 5-30
Software Loopback Example: No Connected Stack Cable, page 5-31
Software Loopback Examples: Connected Stack Cables, page 5-31
Hardware Loopback, page 5-32
Hardware Loopback Example: LINK OK event, page 5-32
Hardware Loop Example: LINK NOT OK Event, page 5-33
Stack Neighbor
Port
Status
------ --------
OK 3
OK 2
OK 1
OK 3
OK 2
OK 1
Stack Neighbor
Port
Status
------ --------
Absent None
OK 2
OK 1
OK 3
OK 2
Down None
Stack Neighbor
Port
Status
------ --------
Down None
OK 3
OK 2
Down None
Cable Link Link
Length OK Active
-------- ---- ------
50 cm Yes Yes
3 m Yes Yes
3 m Yes Yes
50 cm Yes Yes
50 cm Yes Yes
50 cm Yes Yes
Cable Link Link
Length OK Active
-------- ---- ------
No cable No No
3 m Yes Yes
3 m Yes Yes
50 cm Yes Yes
50 cm Yes Yes
50 cm No No
Cable Link Link
Length OK Active
-------- ---- ------
3 m No No
50 cm Yes Yes
50 cm Yes Yes
50 cm No No
Chapter 5 Managing Switch Stacks
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
Yes 1 No
Yes 1 No
Yes 1 No
Yes 1 No
Yes 1 No
Yes 1 No
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
No 1 No
Yes 1 No
Yes 1 No
Yes 1 No
Yes 1 No
No 1 No
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
No 1 No
Yes 1 No
Yes 1 No
No 1 No
OL-12247-04