29
Troubleshooting flowchart
Figure 14 Troubleshooting failure to send packets
Solution
To resolve the problem:
1.
Verify that the ports at both ends are up.
2.
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 all packet counters to 0, so that you can view the statistics changes
more clearly.
b.
Use the
display interface
command to verify that the number of outgoing packets is
accumulating.
c.
Verify that the number of error frames is not accumulating.
If the number of error frames is accumulating, remove the errors. For more information, see
"
Error frames (for example, CRC errors) on a port
."
3.
Verify that the port configurations do not affect packet sending:
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. If configuration errors exist, modify the
port configurations. If the port fails to send packets, use the
shutdown
command and then
the
undo shutdown
command to re-enable the port.
b.
If the port is configured with the spanning tree feature, use the
display stp brief
command
to verify that the port is not in the discarding state.
If the port is set to the discarding state by the spanning tree feature, examine and modify the
spanning tree feature configurations to resolve the problem.
As a best practice, configure the port as an edge port or disable the spanning tree feature on
the port if it is directly connected to a terminal.
A port failed to send packets
Modify port
configuration
End
Port configuration
affects packet receiving?
Problem resolved?
Contact the support
Port and link
medium correct?
Use the correct port
and link medium
Problem resolved?
N
Y
Display packet statistics for
the port
N
N
Y
Y
Y
N
