Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
24
3.4 Network interface communication failures
3.4.1 Ethernet port cannot be connected
If it is possible that the Ethernet port caused the communication failure, check the port
status as described below.
(1) Checking the port status
Use the show port operation command to check the port status. The following table
describes the actions to be taken for the port status.
Table 3-10 Checking the port status and action to take
No
.
Items to check and commands Action
1 Use the show port operation
command to check the status of the
target port.
For dis, continue with No. 2.
For inact, continue with No. 3 through 6.
For down, continue with No. 9.
2 Use the show running-config
operation command to check the
configuration of the target port.
Check whether no shutdown is set for the target port.
If shutdown is set, make sure the cable is connected to the
target port, and then set no shutdown in the configuration.
3 Use the show spanning-tree
operation command with the detail
parameter specified to check the BPDU
guard status of the target port.
If Down and PortFast:BPDUguard(BPDU received) are
displayed for the target port, the BPDU guard functionality of
Spanning Tree is being used, and the port has been blocked
because the target port was receiving BPDs.
Review the settings on the partner switch, and correct the
configuration so that the Switch will not receive BPDUs. Go to
No. 7.
4 Use the show logging operation
command to check the operation log for
storm control.
If STORM:Port<IF#> inactivated because of xxxx
storm detection. is recorded, the port has been blocked
because a storm was detected on the target port.
Use the show logging operation command to make sure the
target port has recovered from the storm. Continue with No. 7.
5 Use the show efmoam operation
command to check the status of the
target port.
If Forced Down is displayed, the port has been blocked
because the IEEE 802.3ah/UDLD functionality detected a
unidirectional link failure.
After correcting the unidirectional link failure according to
3.12
Communication failures in the IEEE 802.3ah/UDLD
functionality, continue with No. 7.
6 Use the show loop-detection
operation command to check the status
of the target port.
If Down(loop) is displayed, the port has been blocked due to
reception of an L2 loop detection frame.
Go to No. 7.
7 Execute the activate operation
command.
Use the show spanning-tree operation command to make
sure that the target port is in the Up status and that
PortFast:BPDUguard(BPDU not received) is displayed.
Use the show logging operation command to make sure the
target port's recovery from the storm has been completed.