Troubleshooting chart
The following table lists symptoms, causes, and solutions for possible problems.
Table 9. Troubleshooting chart
Solution
Cause
Symptom
Check the power cable connections at the switch
and the power source.
Make sure that all cables are used correctly and
comply with the Ethernet specifications.
The switch is not receiving
power.
A Power LED is off.
Check the crimp on the connectors and make sure
that the plug is properly inserted and locked into
the port at both the switch and the connecting
device.
Make sure that all cables are used correctly and
comply with the Ethernet specifications.
Check for a defective port, cable, or module by
testing them in an alternate environment where all
products are functioning.
The port connection is not
working.
A combined speed and
activity LED or an individual
speed LED and an individual
activity LED are off when the
port is connected to a
device.
Break the loop by making sure that only one path
exists from any networked device to any other
networked device. After you connect to the local
browser interface, you can configure the Spanning
Tree Protocol (STP) to prevent network loops.
One possible cause is that a
broadcast storm occurred
and that a network loop
(redundant path) was
created.
A file transfer is slow or the
performance is degraded.
Verify that the cabling is correct.
Make sure that all connectors are securely
positioned in the required ports. It is possible that
equipment was accidentally disconnected.
One or more devices are not
properly connected, or
cabling does not meet
Ethernet guidelines.
A segment or device is not
recognized as part of the
network.
Break the loop by making sure that only one path
exists from any networked device to any other
networked device. After you connect to the local
browser interface, you can configure the Spanning
Tree Protocol (STP) to prevent network loops.
A network loop (redundant
path) was created.
A combined speed and
activity LED or an individual
speed LED and an individual
activity LED are blinking
continuously on all
connected ports and the
network is disabled.
Remove the unit from the stack. Use the local
browser interface to configure the unit as a
stackable unit, with combo links used as the stacking
ports.
The stacking ports of the new
unit are configured
differently from the stack, or
the unit is configured as a
standalone unit.
A unit is linked to a stack but
does not join the stack.
Hardware Installation Guide
68
Maintenance and
Troubleshooting
M4300 Intelligent Edge Series Fully Managed Stackable Switches
