Allied Telesis AT-8100S/24C Installation Manual page 116

Chapter 8: Troubleshooting
116
Problem 3: The stack ID LEDs on the switches of the stack are flashing
the ID numbers and the letter "H" every few seconds.
Solution: This is normal for the LEDs when the switches are operating in
a stack configuration.
Problem 4: All of the port LEDs are off even though the ports are
connected to active network devices.
Solution: The LEDs may have been turned off. To toggle on the LEDs,
press the eco-friendly button on the front panel. It is important to know that
the eco-friendly buttons on the switches in a stack turn on and off the
LEDs only on their respective units.
Problem 5: A twisted pair port on the switch is connected to a network
device but the port's LINK/ACT LED is off.
Solutions: The port is unable to establish a link to a network device. Try
the following:

Verify that the network device connected to the twisted pair port is
powered on and is operating properly.
 Verify that the port is connected to the correct twisted pair cable.
This is to eliminate the possibility that the port is connected to the
wrong network device.
 Try connecting another network device to the twisted pair port with
a different cable. If the twisted pair port is able to establish a link,
then the problem is with the cable or the other network device.
 Verify that the twisted pair cable does not exceed 100 meters (328
feet).
 Verify that you are using the appropriate category of twisted pair
cable. The cable types are listed in Table 6 on page 31 for the 10/
100Base-TX ports and Table 7 on page 33 for the 10/100/
1000Base-T ports.
Note
A 1000Base-T connection may require five to ten seconds to
establish a link.
Problem 6: The LINK/ACT LED for an SFP transceiver is off.
Solutions: The fiber optic port on the transceiver is unable to establish a
link to a network device. Try the following:

Verify that the network device connected to the fiber optic port is
operating properly.
 Verify that the fiber optic cable is securely connected to the port on
the SFP module and to the port on the remote network device.