Cisco Cisco FastHub 412M 10 100 Repeater 릴리즈 노트
8
Troubleshooting
Troubleshooting
Use Table 6 to identify problems with the modules and take the appropriate corrective action.
Table 6
Common Problems and Their Solutions
Symptom
Possible Cause
Corrective Action
Poor performance
or no links
or no links
Incorrect speed settings for 10-Mbps and
100-Mbps connections.
100-Mbps connections.
• Let both ports autonegotiate port speed.
• Set the port speed to match on both ends of the connection.
Cabling distance exceeded.
Port statistics show excessive FCS,
late-collision, or alignment errors.
late-collision, or alignment errors.
For 100BaseTX connections:
• The distance between the port and the
attached device exceeds 100 meters.
• If attached to a repeater, the total distance
between the two end stations exceeds the
100BaseT cabling guidelines.
100BaseT cabling guidelines.
For 10BaseT connections: The distance
between the port and the attached device
exceeds 100 meters.
between the port and the attached device
exceeds 100 meters.
Reduce the cable length to within the recommended distances. See your
100BaseT repeater documentation for cabling guidelines.
100BaseT repeater documentation for cabling guidelines.
Reduce the cable length to within the recommended distances.
Bad adapter in attached device.
Excessive errors found in port statistics.
Run the adapter card diagnostic utility.
Module was not correctly installed.
Ensure the module is firmly in place in the expansion slot and the screws
are inserted and tightened.
are inserted and tightened.
The switched
uplink module is
experiencing
excessive flooding
of unicast packets.
uplink module is
experiencing
excessive flooding
of unicast packets.
Switched uplink module might have
reached the maximum 1536 MAC
addresses in memory and needs to be
cleared.
reached the maximum 1536 MAC
addresses in memory and needs to be
cleared.
Reset the installed switched uplink module to clear the address table.
No connectivity
Incorrect or bad cable.
• A crossover cable was used when
straight-through was required, or
vice-versa.
vice-versa.
• Bad cable.
See the FastHub 400 10/100 Series Installation and Configuration Guide
for the correct pinouts and the proper use of crossover vs.
straight-through cables.
for the correct pinouts and the proper use of crossover vs.
straight-through cables.
Replace with a known good cable.
Port LED off
Devices not powered up.
Ensure both devices have power.
Cable connection loose.
Verify the connection at both ends of cable.
Wrong cable type.
Verify the cable type (crossover vs. straight-through).
Incorrect wiring.
See the FastHub 400 10/100 Series Installation and Configuration Guide
for pinout information.
for pinout information.
Faulty cable.
Replace the cable with a known good one.
Port LED solid
amber
amber
Port not forwarding.
The port might be disabled by management,
or the device at other end is malfunctioning.
or the device at other end is malfunctioning.
Enable the port through in-band or out-of-band management.
Investigate the device that is connected to the disabled port on the hub.