Allied Telesis x310 Series - Manual (Page 108)

Chapter 7: Troubleshooting
108
 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 2 on page 26 for the 10/
100/1000Base-T ports.
Note
A 1000Base connection may require five to ten seconds to establish
a link.
Problem 4: 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 remote 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.
 Check that the transceiver is fully inserted in the slot.
 Check to be sure that the transceiver is not installed in slot S1 or
S2 in the switch. These slots are for AT-Stack transceivers only.
 Verify that the operating specifications of the fiber optic ports on
the transceiver and remote network device are compatible.
 Verify that the correct type of fiber optic cabling is being used.
 Verify that the port is connected to the correct fiber optic cable.
This is to eliminate the possibility that the port is connected to the
wrong remote network device.
 Try connecting another network device to the fiber optic port using
a different cable. If the port is able to establish a link, then the
problem is with the cable or with the other network device.
 Use the switch’s management software to verify that the port is
enabled.
 If the remote network device is a managed device, use its
management firmware to determine whether its port is enabled.
 Test the attenuation of both directions on the fiber optic cable with
a fiber optic tester to determine whether the optical signal is too
weak (sensitivity) or too strong (maximum input power).