Software Loopback Example: No Connected Stack Cable; Software Loopback Examples: Connected Stack Cables - Cisco Catalyst 2975 Software Configuration Manual

Troubleshooting Stacks
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
Switch 1 is a standalone switch.
Switch# show switch stack-ports summary
Switch#/
Port#
--------
1/1
1/2

Software Loopback Example: No Connected Stack Cable

Catalyst 2975 switch port status:
Switch# show switch stack-ports summary
Switch#/
Port#
--------
1/1
1/2

Software Loopback Examples: Connected Stack Cables

•
•
Catalyst 2975 Switch Software Configuration Guide
6-26
Stack Neighbor
Port
Status
------ --------
Down None
OK 3
OK 2
Down None
Stack Neighbor
Port
Status
------ --------
Absent None
Absent None
Stack Neighbor
Port
Status
------ --------
Absent None
Absent None
On Port 1 on Switch 1, the port status is Down, and a cable is connected.
On Port 2 on Switch 1, the port status is Absent, and no cable is connected.
Switch# show switch stack-ports summary
Switch#/ Stack Neighbor
Port# Port
Status
-------- ------ --------
1/1 Down None
1/2 Absent None
In a physical loopback, a cable connects both stack ports on a switch. You can use this configuration
to test
Cables on a switch that is running properly
–
Stack ports with a cable that works properly
–
Switch# show switch stack-ports summary
Switch#/ Stack Neighbor
Port# Port
Status
-------- ------ --------
2/1 OK 2
2/2 OK 2
Cable Link Link
Length OK Active
-------- ---- ------
3 m No No
50 cm Yes Yes
50 cm Yes Yes
50 cm No No
Cable Link Link
Length OK Active
-------- ---- ------
No cable No No
No cable No No
Cable Link Link
Length OK Active
-------- ---- ------
No cable Yes No
No cable Yes No
Cable Link Link
Length OK Active
-------- ---- ------
50 Cm No No
No cable No No
Cable Link Link
Length OK Active
-------- ---- ------
50 cm Yes Yes
50 cm Yes Yes
Chapter 6 Managing Switch Stacks
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
No 1 No
Yes 1 No
Yes 1 No
No 1 No
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
No 1 Yes
No 1 Yes
Sync # In
OK Changes Loopback
To LinkOK
---- --------- --------
Yes 1 Yes
Yes 1 Yes
Sync #
OK Changes Loopback
To LinkOK
---- --------- --------
No 1
No 1
Sync #
OK Changes Loopback
To LinkOK
---- --------- --------
Yes 1
Yes 1
In
No
No
In
No
No
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