Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
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5. If a log entry was not displayed for the date and time when communication was disabled, see
(2) Checking the interface status.
(2) Checking the interface status
Even when the Switch hardware is operating normally, a fault could have occurred on the hardware
of a neighboring device connected to the Switch.
To check the status of the interface between the Switch and the neighboring device, do the
following:
1. Log in to the Switch.
2. Use the
show ip interface command to check whether the status of the interface with the
target neighboring device is
Up or Down.
3. For AX6700S, AX6600S, and AX6300S series switches, if the target interface working as a
VRF interface is not displayed, see (9) Checking the optional license OP-NPAR.
4. If the status of the target interface is
Down, see 3.5 Network interface communication failures.
5. If the status of the target interface is
Up, see (3) Identifying the range for a failure (from the
Switch).
(3) Identifying the range for a failure (from the Switch)
If a failure has not occurred on the Switch, a failure might have occurred somewhere on the route
between the Switch and the remote devices. To identify the range for a failure in order to determine
the fault location on the route, do the following:
1. Log in to the Switch.
2. Use the
ping command to check the communication with the two remote devices that are
unable to communicate. For details about examples of using the
ping command and how to
interpret the execution result, see the Configuration Guide.
3. If communication with the remote devices cannot be verified by the
ping command, execute
the command again to check communication with each of the devices up to the remote device,
beginning with the device closest to the Switch.
4. If the execution result of the
ping command indicates that the failure occurred on the
neighboring device, see (5) Checking the ARP resolution information with a neighboring
device. If the execution result indicates a failure on the remote device, see (6) Checking the
unicast routing information.
(4) Identifying the range for a failure (from a customer's terminal)
To use the customer's terminal to identify the range for a failure so that you can determine the fault
location on the route with a remote device in an environment in which login to the Switch is not
possible, do the following:
1. Make sure the customer's terminal has the
ping functionality.
2. Use the
ping functionality to check whether communication between the customer's terminal
and the remote device is possible.
3. If communication with the remote device cannot be verified by using the
ping functionality,
use the
ping command to check communication with each of the devices up to the remote
device, beginning with the device closest to the customer's terminal.
4. If you are able to determine the range for the failure by using the
ping functionality and
pinpoint the Switch that is likely to have the failure, log in to the Switch and investigate the
cause of the failure based on the failure analysis flowchart.
(5) Checking the ARP resolution information with a neighboring device
If the execution result of the
ping command indicates that communication with a neighboring