6-26
Catalyst 2975 Switch Software Configuration Guide
OL-19720-02
Chapter 6 Managing Switch Stacks
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#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
2/1 Down None 3 m No No No 1 No
2/2 OK 3 50 cm Yes Yes Yes 1 No
3/1 OK 2 50 cm Yes Yes Yes 1 No
3/2 Down None 50 cm No No No 1 No
Switch 1 is a standalone switch.
Switch#
show switch stack-ports summary
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 Absent None No cable No No No 1 Yes
1/2 Absent None No cable No No No 1 Yes
Software Loopback Example: No Connected Stack Cable
Catalyst 2975 switch port status:
Switch#
show switch stack-ports summary
Switch#/ Stack Neighbor Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 Absent None No cable Yes No Yes 1 Yes
1/2 Absent None No cable Yes No Yes 1 Yes
Software Loopback Examples: Connected Stack Cables
•
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 Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
1/1 Down None 50 Cm No No No 1 No
1/2 Absent None No cable No No No 1 No
•
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 Cable Link Link Sync # In
Port# Port Length OK Active OK Changes Loopback
Status To LinkOK
-------- ------ -------- -------- ---- ------ ---- --------- --------
2/1 OK 2 50 cm Yes Yes Yes 1 No
2/2 OK 2 50 cm Yes Yes Yes 1 No