5-26
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter5 Managing Switch Stacks
Troubleshooting Stacks
Identifying Loopback Problems
Software Loopback, page5-27
Software Loopback Example: No Connected StackWise Cable, page5-28
Software Loopback Examples: Connected StackWise Cables, page5-28
Hardware Loopback, page5-29
Table5-5 show switch stack-ports summary Command Output
Field Description
Switch#/Port# Member number and its StackWise port number.
Stack Port Status Absent—No cable is detected on the StackWise port.
Down—A cable is detected, but either no connected neighbor is up,
or the StackWise port is disabled.
OK—A cable is detected, and the connected neighbor is up.
Neighbor Switch number of the active member at the other end of the StackWise
cable.
Cable Length Valid lengths are 50 cm, 1 m, or 3 m.
If the switch cannot detect the cable length, the value is no cable. The
cable might not be connected, or the link might be unreliable.
Link OK This shows if the link is stable.
The link partner is a StackWise port on a neighbor switch.
No—The link partner receives invalid protocol messages from the
port.
Yes—The link partner receives valid protocol messages from the
port.
Link Active This shows if the StackWise port is in the same state as its link partner.
No—The port cannot send traffic to the link partner.
Yes—The port can send traffic to the link partner.
Sync OK No—The link partner does not send valid protocol messages to the
StackWise port.
Yes—The link partner sends valid protocol messages to the port.
# Changes to LinkOK This shows the relative stability of the link.
If a large number of changes occur in a short period of time, link flapping
can occur.
In Loopback No—At least one StackWise port on the member has an attached
StackWise cable.
Yes—None of the StackWise ports on the member has an attached
StackWise cable.