Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
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3.5.6 Actions to be taken for PoE problems
If a problem such as a disabled power supply unit occurs when PoE is used, isolate the cause of the
problem according to the failure analysis method described in the following table.
3 For AX6700S, AX6600S, or
AX6300S series switches,
use the
show interfaces
command to display the
failure statistics, and check
whether there is a count for
the following item for the
target port. If there is a
count, see the Cause and
Action columns.
• RF
Line quality on
the sending side
is degraded.
Check the type of the optical fiber. For the types, see the
Hardware Instruction Manual.
If an optical attenuator is used, check the attenuation value. For
the optical level, see the Hardware Instruction Manual.
Check the cable length. For the cable length, see the Hardware
Instruction Manual.
Check whether the cables are connected correctly (for
example, check for incomplete insertion). Make sure that the
end sections of the cables are clean. If they are dirty, clean
them.
Check whether the transceiver is connected correctly.
Adjust the transceiver to comply with the segment standard of
the remote device.
Check whether the optical level is correct. For the optical level,
see the Hardware Instruction Manual.
Perform a line test on the Switch and make sure that the
functionality of the sending side has no problem. Check the
results of the
no test interfaces command, and take the
action described in Action. For the test types to be specified,
see 6.1 Testing a line.
4Use the
show interfaces
command to display the
failure statistics, and check
whether there is a count for
the following item for the
target port. If there is a
count, see the Cause and
Action columns.
• Long frames
Packets
exceeding the
maximum
allowed frame
length are
received.
Adjust the jumbo frame settings to those on the remote device.
5Use the
show qos
queueing command to
check whether there is a
count for the following item.
If there is a count, see the
Cause and Action columns.
• discard_pkt
Packets are
discarded.
Check whether drop control and the shaper are being used
appropriately in the system configuration.
No. Items to check Cause Action