Alaxala AX2500S, Руководство по устранению неисправностей

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3 Troubleshooting Functional Failures During Operation
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3.9 Communication failures in the high-reliability functionality based
on a redundant configuration
3.9.1 Communication failures occurring when uplink redundancy is used
If switching cannot be performed as expected when uplink redundancy is used, isolate the
cause of the problem according to the failure analysis method described in the following
table.
Table 3-28 Failure analysis method for uplink redundancy
No. Items to check and commands Action
1 Use the
show
switchport-backup
operation
command to check the primary and
secondary pair information.

Pair information is not displayed: Go to No. 2.

Pair information is displayed:
- If the
Status
information for the port displayed by the
show switchport-backup
operation command does not
change immediately after the physical port enters the
link-down status, go to No. 3.
- If automatic preemption or timer preemption is not possible
after the primary port enters the link-up status, go to No. 4.
2 Use the
show running-config
operation command to check the
uplink redundancy configuration.
The port channel interface is specified for the secondary port:
The configuration for the target port channel interface might have
not been set.
Check the configuration of the target port channel interface. If the
configuration has not been set, set it.
3 Check the link debounce setting for
the target port. If the
link debounce
configuration command has not been set
(that is, the default of 2000 milliseconds is used for operation) or if
a value greater than
2000
(milliseconds) is set, reduce the set
value.
4
If automatic preemption or timer
preemption to the primary port is not
possible, use the
show
switchport-backup
operation
command to check the information
displayed for
Status
for the
primary port.

Blocking
displayed:
- If a hyphen (
-
) is displayed for
Delay
under
Preemption
,
neither automatic preemption nor timer preemption has been
set. Use the
switchport backup interface
configuration command to set preemption.
- If a value other than
0
is displayed for
Limit
(time) under
Preemption
, the preemption time has not been reached.
Wait a while.
Alternatively, execute the
set switchport-backup
active operation command.

Down
displayed:
The status of the port is link down. Check the status of the
upstream switch and the cable connection.

For other cases, go to No. 5.
5 Check whether a Spanning Tree
Protocol is running on the upstream
switch of the primary port. When a Spanning Tree Protocol is running, the port enters the
Listening or Learning status after recovery from a link-down
condition, and therefore communication is disabled for a while. If a
Spanning Tree Protocol is running on the upstream switch, set the
timer preemption to 30 seconds or longer.
For other cases, go to No. 6.
6 Check whether the upstream switch
can receive flush control frames. Reception is possible: Go to No. 7.
Reception is not possible: Go to No. 8.