Finding A Disconnected Stack Cable - Cisco Catalyst 3750-X Software Configuration Manual

Troubleshooting Stacks
On a Catalyst 3750-E or 3750-X switch:
Switch# show platform stack ports buffer
Stack Debug Event Data Trace
==============================================================
Event type LINK: Link status change
Event type RAC: RAC changes to Not OK
Event type SYNC: Sync changes to Not OK
==============================================================
Event
Count
=========
Event type: LINK OK Stack Port 1
0000000014
0000000014
Event type: RAC
0000000015
0000000015
Event type: LINK OK Stack Port 2
0000000029
0000000029
Event type: RAC
0000000030
0000000030
Event type: LINK NOT OK Stack Port 1
0000009732
0000009732
Event type: RAC
0000009733
0000009733
Event type: LINK NOT OK Stack Port 2
0000010119
0000010119
Event type: RAC
0000010120
0000010120

Finding a Disconnected Stack Cable

Stack cables connect all stack members. Port 2 on Switch 1 connects to Port 1 on Switch 2.
This is the port status for the members:
Switch# show switch stack-ports summary
Switch#/
Port#
--------
1/1
1/2
2/1
2/2
If you disconnect the cable from Port 2 on Switch 1, these messages appear:
%STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 2 has changed to state DOWN
%STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 1 has changed to state DOWN
This is now the port status:
Switch# show switch stack-ports summary
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
5-32
Stack Stack PCS Info
Port
===== ===================================
1 FF01FF00 860204A7 5555FFFF 00000000
2 FF01FF00 85020823 AAAAFFFF 00000000
1 FF01FF00 860204A7 5555FFFF 00000000
2 FF01FF00 85020823 AAAAFFFF 00000000
1 FF01FF00 860204A7 5555FFFF 00000000
2 FF01FF00 86020823 AAAAFFFF 00000000
1 FF01FF00 860204A7 5555FFFF 00000000
2 FF01FF00 86020823 AAAAFFFF 00000000
1 FF01FF00 00015B12 5555FFFF A49CFFFF
2 FF01FF00 86020823 AAAAFFFF 00000000
1 FF01FF00 00015B4A 5555FFFF A49CFFFF
2 FF01FF00 86020823 AAAAFFFF 00000000
1 FF01FF00 00010E69 25953FFF FFFFFFFF
2 FF01FF00 0001D98C 81AAC7FF 0300FFFF
1 FF01FF00 00010EEA 25953FFF FFFFFFFF
2 FF01FF00 0001DA0C 81AAC7FF 0300FFFF
Stack Neighbor Cable
Port Length
Status
------ -------- --------
OK 2 50 cm
OK 2 50 cm
OK 1 50 cm
OK 1 50 cm
Ctrl-Status
===========
0CE60CA6
0CE60CA6
0CE60CA6
0CE60CA6
1CE61CE6
1CE61CE6
1CE61CE6
1CE61CE6
0C140CE4
0C140CE4
0C140CE4
0C140CE4
0C140C14
0C140C14
0C140C14
0C140C14
Link Link Sync
OK Active OK Changes
To LinkOK
---- ------ ---- ---------
Yes Yes Yes
Yes Yes Yes
Yes Yes Yes
Yes Yes Yes
Chapter 5 Managing Switch Stacks
Loopback Cable
IOS / HW length
======== ========
No /No 50 cm
No /No 3 m
No /No 50 cm
No /No 3 m
No /No 50 cm
No /No 3 m
No /No 50 cm
No /No 3 m
No /No 50 cm
No /No 3 m
No /No 50 cm
No /No 3 m
No /Yes No cable
No /No 3 m
No /Yes No cable
No /No 3 m
# In
Loopback
--------
0 No
0 No
0 No
0 No
OL-21521-01