Cisco GigaStack WS-X3500-XL User Manual
Page 48
Chapter 3
Troubleshooting
3-2
Catalyst GigaStack Gigabit Interface Converter Hardware Installation Guide
78-6460-04
GigaStack GBIC 
LED blinks any 
color for more than 
1 minute.
Link flap (the link keeps 
going up and down).
Remove and reinsert the GigaStack GBIC.
Upgrade all the switches in a series to the same 
software version; otherwise, the loop-breaking 
algorithm might never resolve itself. For example, 
if the stack includes only Catalyst 2900 series XL 
and 3500 series XL switches, they must run 
Release 12.0(5)XU or later. If the stack includes a 
mixture of Catalyst 2900 series XL, 
3500 series XL, 2950, and 3550 switches, all the 
2900 XL and 3500 XL switches must run 
Release 12.0(5)XW or later, all Catalyst 2950 
switches must run Release 12.1(6)EA2 or later, 
and all Catalyst 3550 switches must run 
Release 12.1(4)EA1 or later.
If no loop exists in the GigaStack GBIC stack, you 
can disable the loop-breaking algorithm by using 
the no gigastack loop-breaking [interface-id] 
global configuration command.
GigaStack GBIC 
LED color is 
incorrect (for 
example, the GBIC 
is not connected to 
another device, but 
the LED is green).
The GigaStack GBIC is in 
an indeterminate state.
Remove and reinsert the GigaStack GBIC.
Table 3-1
Common Problems and Their Solutions (continued)
Symptom
Possible Causes
Corrective Action