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Interface failure
Each interface has a corresponding LED. When an interface connected to the network works properly, the
corresponding LINK LED is on. If the LED of an interface connected to the network is off, the interface or the
connecting cable may fail.
To troubleshoot the interface:
1.
Check whether the switch works properly.
2.
Check the cable connection of the interface. For how to correctly connect the cable to an Ethernet
interface with a RJ-45 connector or an optical interface, see the chapter ―
Connecting the switch to the
network
.‖
3.
Check whether the cable fails. Use the cable to connect two interfaces of the same type that work
properly. If the LEDs of the two interfaces are on, the cable is normal. Otherwise, the cable fails.
4.
If the interface uses a transceiver module, check that the interface type is compatible with the
transceiver module and the transceiver module is compatible with the cable.
5.
If the interface uses a transceiver module, make sure that the current transceiver module works
properly by replacing a normal transceiver module.
6.
If the interface is a combo interface (which comprises a copper port and a fiber port), make sure that
the interface used for connecting is activated for the combo interface. Then, use the
combo enable
{
copper
|
fiber
} command in interface view to activate the port, and check the LED.
NOTE:
Each combo interface has one fiber SFP port and one copper Ethernet port. These two ports share one
port name and port view and cannot work simultaneously. When you activate one port (by using the
combo enable
{
copper
|
fiber
} command), the other port automatically shuts down.
After an interface fails, if the switch has an idle interface of the same type, you can plug the cable into
the idle interface.
7.
Check that the speed and duplex settings of the interfaces of a link are the same. Make sure that two
interfaces can work together.
PoE system failure
If a PoE-capable switch cannot supply power to a powered device (PD) attached to the switch, follow these
steps to troubleshoot the PoE system:
1.
Check that the power cable that connects the switch to the PD is a straight-through cable.
2.
Make sure that the PoE-related configurations are correct. For how to configure PoE, see the related
configuration guide.
3.
Check the temperature of the switch. The PoE-capable switch provides the overtemperature protection
mechanism. When the internal temperature of the switch exceeds 65°C (149°F), the switch performs
self protection and disables PoE on all ports. When the internal temperature drops below 60°C
(140°F), the switch enables PoE on all ports.
