Chapter 3: Troubleshooting
50 Section II: Advanced Operations
Verify that the operating specifications of the fiber optic port on the
remote network device are compatible with the port on the media
converter. For port specifications, refer to “100Base-FX Port
Specifications” on page55.
Verify that the correct type of fiber optic cabling is being used. For
specifications, refer to “Fiber Optic Cabling and Distance
Specifications” on page35 or “100Base-FX Port 1 Specifications” on
page 55.
Try connecting another network device to the fiber optic port using 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.
If the remote network device is a management device, use its
management firmware to determine whether its port is enabled.
Test the attenuation on the fiber optic cable with a fiber optic tester to
determine whether the optical signal is too weak (i.e., sensitivity) or too
strong (i.e., maximum input power). The specifications of the fiber
optic ports on the media converter can be found in “100Base-FX Port 1
Specifications” on page55.
Problem 4: The Link LEDs for the two ports are on but the network
devices are unable to forward traffic to each other through the media
converter.
Solution: Try the following:
If the network devices are managed devices, use their management
firmware to determine whether they are configured and operating
properly.
If one of the network devices is a switch using a spanning tree
protocol, use its management firmware to determine the status of the
switch port connected to the media converter. The port may have been
placed in the blocking mode by the switch if it is part of a redundant
path.
Problem 5: Two network devices are forwarding traffic through the media
converter, but performance is slow.
Solution: Try the following:
There might be a duplex mode mismatch between the twisted pair port
and the network device connected to the port. A duplex mode
mismatch occurs when a twisted pair port using Auto-Negotiation is
connected to a device with a fixed duplex mode of full duplex. If this is
the cause of the problem, you must adjust the duplex mode of the port
on the network device or the twisted pair port on the media converter
so that both ports are using the same duplex mode.