edge switch 2/32 product manager user guide

edge switch 2/32 product manager user guide 2–35
Monitoring and Managing the Switch
• Invalid transmission words — The number of times that the Switch detected
invalid transmission words from the attached device. This indicates that a frame or
primitive sequence arrived at the Switch’s port corrupted. This corruption can be
due to the attached device performing a reset, plugging or unplugging the link,
bad optics at either end of the cable, bad cable, or a dirty or poor connection.
Moving the connection around or replacing cables can isolate the problem.
Some number of invalid transmission words are expected and acceptable. Invalid
transmission words within a frame are used to produce the bit-error threshold link
incident. If one or more invalid transmission words are detected in 12 separate
1.5-second samples within five minutes, a bit-error threshold link incident is
generated.
• CRC errors — A received frame failed a cyclic redundancy check (CRC)
validation, indicating the frame arrived at the Switch’s port corrupted. Frame
corruption may be caused by device disconnection, an optical transceiver failure at
the device, a bad fiber-optic cable, or a poor cable connection.
• Delimiter errors — The number of times that the Switch detected an
unrecognized start-of-frame (SOF), an unrecognized end-of-frame (EOF)
delimiter, or an invalid class of service. This indicates that the frame arrived at the
Switch’s port corrupted. This corruption can be due to plugging/unplugging the
link, bad optics at either end of the cable, bad cable, or dirty or poor connections.
Moving the connection around or replacing cables can isolate the problem.
• Address ID errors — A received frame had an unavailable or invalid Fibre
Channel destination address, or an invalid Fibre Channel source address. This
typically indicates the destination device is unavailable.
• Frames too short — A received frame exceeded the Fibre Channel frame
maximum size or was less than the Fibre Channel minimum size, indicating the
frame arrived at the Switch’s port corrupted. Frame corruption may be caused by
device disconnection, an optical transceiver failure at the device, a bad fiber-optic
cable, or a poor cable connection.
Troubleshooting Tips
As a general rule, you should clear all counts after the system is stabilized. When
looking at the Performance view, roughly keep track of the time interval when
errors accumulate to judge the presence and severity of a problem. Also, recognize
that there is a link recovery hierarchy implemented in Fibre Channel to handle
some level of “expected anomalies.” In general, only be concerned with error
counts that increment very quickly.