Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
142
3.17 Communication failures in the neighboring device management
functionality
3.17.1 Neighboring device information cannot be obtained by the LLDP
functionality
If neighboring device information cannot be obtained correctly by using the LLDP functionality,
isolate the cause of the problem according to the failure analysis method described in the following
table.
Table 3-73: Failure analysis method when the LLDP functionality is used
3.17.2 Neighboring device information cannot be obtained by the OADP
functionality
If neighboring device information cannot be obtained correctly by using the OADP functionality,
isolate the cause of the problem according to the failure analysis method described in the following
table.
No. Items to check and commands Action
1 Execute the show lldp command and
check the operating status of the LLDP
functionality.
If
Enabled is displayed for Status, go to No. 2.
If the displayed status is
Disabled, the LLDP functionality has been
disabled. Enable the LLDP functionality.
2 Execute the
show lldp command and
check the port information.
If information for the port to which the neighboring device is connected
is displayed, go to No. 3.
If information for the port to which the neighboring device is connected
is not displayed, the LLDP functionality is disabled for the target port.
Enable the LLDP functionality for the target port.
3 Execute the
show lldp statistics
command and check the statistics for
the port to which the neighboring device
is connected.
If the
Tx count has been incremented but the Rx count has not, check No.
1 through No. 3 on the neighboring device. If the
Tx count has also been
incremented on the neighboring device, the connection between the
devices might be incorrect. Check the connection.
If the
Discard count has been incremented, check the connection
between the devices.
For other cases, go to No. 4.
4 Execute the
show lldp command and
check the port status in the information
for the port to which the neighboring
device is connected.
If
Up is displayed for Link, go to No. 5.
If
Down is displayed for Link, check the line status. For details about the
check procedure, see 3.5 Network interface communication failures.
5 Execute the
show lldp command, and
check the number of neighboring device
information items on the port to which
the neighboring device is connected.
If
0 is displayed for Neighbor Counts, check No. 1 through No. 5 on
the neighboring device. If the number of neighboring device information
items is also
0 on the neighboring device, the connection between the
devices might be incorrect. Check the connection.
Also, LLDP control frames might have been discarded by filters or QoS
control. See 3.25.1 Checking the filters and QoS configuration
information.