Solution - H3C S5560-EI Series Troubleshooting Manual

Solution

To resolve the problem:
1. Examine the packet statistics of the port:
a. (Optional.) Use the reset counter interface command to clear the packet statistics of the port.
This command resets the values of each statistical field to 0, so that you can view the statistics
changes more clearly.
b. Determine whether the ports at both ends are always up, and use the display interface
command to determine whether the number of incoming packets is accumulating. At the same
time, examine the outgoing packet statistics of the peer port.
c. View the values of the error packet fields and determine whether the number of error packets
is accumulating.
2. Verify that the port configurations do not affect packet receiving:
a. Use the display interface brief command to verify that the port configurations are correct.
The port configurations include the duplex mode, speed, port type, and VLAN configurations
of the ports at both ends of the link.
b. If configuration errors exist, modify the port configurations. If the number of incoming packets
in the output from the display interface command is accumulating, you can determine that the
port can receive packets.
c. If the port fails to receive packets, use the shutdown command and then the undo shutdown
command to re-enable the port. If the number of incoming packets in the output from the
display interface command is accumulating, you can determine that the port can receive
packets.
d. If the port is configured with STP, use the display stp brief command to verify that the port is not
in the discarding state.
e. If a port is set to the discarding state by STP, examine and modify the STP-related
configurations to resolve the problem.
H3C recommends that you configure the port as an edge port or disable STP on the port if it is
directly connected to a terminal.
If the port is assigned to an aggregation group, use the display link-aggregation summary
f.
command to verify that the status of the port is Selected.
g. If the status of the port is Unselected, the port cannot send or receive data packets.
h. Determine the reasons why the port becomes Unselected, for example, the attribute
configurations of the port are different from the reference port. Modify the attribute
configurations of the port to make the port become Selected.
3. Verify that the port and the link medium are operating correctly:
a. Plug the link medium into another port that is operating correctly, and determine whether the
same problem occurs.
b. If the problem still occurs, verify that the following items are operating correctly:
−
−
c. Examine the port.
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Intermediate links and devices, including optical-to-electrical converters, cable terminal
racks, and transmission devices.
Transmission medium, including network cables, optical fibers, and transceiver modules.
If the port is a copper port, directly connect the port to a PC.
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