H3C S5850-54QS User manual

H3C S5850 Switch Series
Troubleshooting Guide
Document version: 6W100-20201218
Copyright © 2020 New H3C Technologies Co., Ltd. All rights reserved.
No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of New
H3C Technologies Co., Ltd.
Except forthe trademarks of NewH3C Technologies Co.,Ltd., anytrademarks that may be mentioned in this document are
the property of their respective owners.
The information in this document is subject to change without notice.

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Contents
Introduction····································································································1
General guidelines·············································································································································1
Collecting log and operating information············································································································1
Collecting common log messages ·············································································································2
Collecting diagnostic log messages···········································································································3
Collecting operating statistics·····················································································································3
Contacting technical support······························································································································4
Troubleshooting hardware·············································································4
Unexpected switch reboot··································································································································5
Symptom····················································································································································5
Troubleshooting flowchart··························································································································5
Solution······················································································································································5
Operating power module failure·························································································································6
Symptom····················································································································································6
Troubleshooting flowchart··························································································································6
Solution······················································································································································6
Newly installed power module failure·················································································································7
Symptom····················································································································································7
Troubleshooting flowchart··························································································································7
Solution······················································································································································7
Fan tray failure···················································································································································8
Symptom····················································································································································8
Troubleshooting flowchart··························································································································8
Solution······················································································································································8
Related commands············································································································································9
Troubleshooting ACL···················································································10
ACL application failure with an error message·································································································10
Symptom··················································································································································10
Troubleshooting flowchart························································································································10
Solution····················································································································································10
ACL application failure without an error message····························································································10
Symptom··················································································································································10
Troubleshooting flowchart························································································································11
Solution····················································································································································11
Packet loss or forwarding failure······················································································································12
Symptom··················································································································································12
Troubleshooting flowchart························································································································12
Solution····················································································································································13
Related commands··········································································································································14
Troubleshooting IRF····················································································16
IRF fabric establishment failure························································································································16
Symptom··················································································································································16
Troubleshooting flowchart························································································································17
Solution····················································································································································17
Related commands··········································································································································19
Troubleshooting Ethernet link aggregation···················································20
Link aggregation failure····································································································································20
Symptom··················································································································································20
Troubleshooting flowchart························································································································21
Solution····················································································································································21
Related commands··········································································································································22

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Troubleshooting ports··················································································23
Fiber port remains in down state······················································································································23
Symptom··················································································································································23
Troubleshooting flowchart························································································································23
Solution····················································································································································24
Copper port remains in down state··················································································································25
Symptom··················································································································································25
Troubleshooting flowchart························································································································25
Solution····················································································································································25
Non-H3C transceiver module···························································································································26
Symptom··················································································································································26
Troubleshooting flowchart························································································································26
Solution····················································································································································26
Transceiver module does not support digital diagnosis···················································································27
Symptom··················································································································································27
Troubleshooting flowchart························································································································28
Solution····················································································································································28
Error frames (for example, CRC errors) on a port····························································································29
Symptom··················································································································································29
Troubleshooting flowchart························································································································29
Solution····················································································································································29
Failure to receive packets································································································································31
Symptom··················································································································································31
Troubleshooting flowchart························································································································31
Solution····················································································································································31
Failure to send packets····································································································································33
Symptom··················································································································································33
Troubleshooting flowchart························································································································33
Solution····················································································································································33
Related commands··········································································································································34
Troubleshooting system management·························································36
High CPU utilization·········································································································································36
Symptom··················································································································································36
Troubleshooting flowchart························································································································36
Solution····················································································································································36
High memory utilization····································································································································38
Symptom··················································································································································38
Troubleshooting flowchart························································································································38
Solution····················································································································································38
Related commands··········································································································································39
Troubleshooting other issues·······································································40
Layer 2 forwarding failure·································································································································40
Symptom··················································································································································40
Troubleshooting flowchart························································································································41
Solution····················································································································································41
Related commands··································································································································45
Layer 3 forwarding failure·································································································································46
Symptom··················································································································································46
Troubleshooting flowchart························································································································46
Solution····················································································································································47
Related commands··································································································································47
Protocol flapping ··············································································································································47
Symptom··················································································································································47
Troubleshooting flowchart························································································································48
Solution····················································································································································48
Fan tray failure·················································································································································49
Symptom··················································································································································49
Troubleshooting flowchart························································································································49
Solution····················································································································································49

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Related commands··································································································································50

1
Introduction
This document provides information about troubleshooting common software and hardware issues
with S5850 Switch Series.
This document is not restricted to specific software or hardware versions.
General guidelines
IMPORTANT:
To prevent a failure from causing loss of configuration, save
the configuration each time you finish
configuring a feature. For configuration recovery, regularly back up the configuration to a remote
server.
When you troubleshoot an issue, follow these general guidelines:
•
To help identify the failure cause, collect system and configuration information, including:
Symptom, time of failure, and configuration.
Network topology information, including the network diagram, port connections, and points
of failure.
Log messages and diagnostic information. For more information about collecting this
information, see "Collecting log and operating information."
Physical evidence of failure:
−Photos of hardware.
−Status of the LEDs.
Measures you have taken, such as reconfiguration, cable swapping, and reboot.
Output from the commands executed during the troubleshooting process.
•
To ensure safety, wear an ESD-preventive wrist strap when you replace or maintain a hardware
component.
•
If hardware replacement is required, use the release notes to verify the hardware and software
compatibility.
Collecting log and operating information
IMPORTANT:
To
facilitate troubleshooting, enable the following features:
•
Information center—To enable the information center, execute the info-center enable command.
•
Log file—To enable the log file feature, execute the info-center logfile enable command.
•
Saving diagnostic log messages to the diagnostic log file—To enable this feature, execute the
info-center diagnostic-logfile enable command.
By default, these features are enabled.
Table 1 shows the types of files that the system uses to store operating log and status information.
Common log files are stored in the flash:/logfile directory and diagnostic log files are stored in the
flash:/diagfile directory. You can export these files by using FTP, TFTP, or USB.
In an IRF system, these files are stored on the master device. If master/subordinate switchovers
have occurred, master devices before and after the switchovers have log files. You must collect log

2
files from all these devices. To more easily locate log information, save log files to a separate folder
for each member device and include their IRF member IDs in the folder names.
Table 1 Log and operating information
Category
File name format
Content
Common log logfile.log Log messages about command executions, event occurrences,
and state changes.
Diagnostic log diagfile.log
Diagnostic log messages about device operation, including the
following items:
•Parameter settings used when an error occurs.
•Information about a card startup error.
•Handshaking information between member devices when
a communication error occurs.
Operating
statistics file-basenam.tar.gz
IMPORTANT:
Current operation statistics for feature modules, including the
following items:
•Device status.
•CPU status.
•Memory status.
•Configuration status.
•Software entries.
•Hardware entries.
Collecting common log messages
1. Save the common log messages from the log buffer to a log file.
By default, the log file is saved in the logfile directory of the flash memory on each member
device.
<Sysname> logfile save
The contents in the log file buffer have been saved to the file
flash:/logfile/logfile.log
2. Identify the log file on each member device:
# Display the log file on the master device.
<Sysname> dir flash:/logfile/
Directory of flash:/logfile
0 -rw-21863 Jul 11 2013 16:00:37 logfile.log
524288 KB total (107944 KB free)
# Display the log file on each subordinate device.
This example uses slot 2.
<Sysname> dir slot2#flash:/logfile/
Directory of slot2#flash:/logfile
0 -rw-21863 Jul 11 2013 16:00:37 logfile.log
524288 KB total (107944 KB free)
3. Transfer the files to the desired destination by using FTP, TFTP, or USB. (Details not shown.)

3
Collecting diagnostic log messages
1. Save the diagnostic log messages from the diagnostic log file buffer to a diagnostic log file.
By default, the diagnostic log file is saved in the diagfile directory of the flash memory on each
member device.
<Sysname> diagnostic-logfile save
The contents in the diagnostic log file buffer have been saved to the file
flash:/diagfile/diagfile.log
2. Identify the diagnostic log file on each member device:
# Display the diagnostic log file on the master device.
<Sysname> dir flash:/diagfile/
Directory of flash:/diagfile
0 -rw-161321 Jul 11 2013 16:16:00 diagfile.log
524288 KB total (107944 KB free)
# Display the diagnostic log file on each subordinate device:
<Sysname> dir slot2#flash:/diagfile/
<Sysname> dir slot2#flash:/diagfile/
Directory of slot2#flash:/diagfile
0 -rw-161321 Jul 11 2013 16:16:00 diagfile.log
524288 KB total (107944 KB free)
3. Transfer the files to the desired destination by using FTP, TFTP, or USB. (Details not shown.)
Collecting operating statistics
You can collect operating statistics by saving the statistics to a file or displaying the statistics on the
screen.
When you collect operating statistics, follow these guidelines:
•
Log in to the device through a network port or management port (if any) instead of the console
port as long as possible. Network and management ports are faster than the console port.
•
Do not execute commands during operating statistics collection.
•
To ensure information completeness, save the statistics to a file as a best practice.
NOTE:
The amount of time to collect statistics increases along with the number of IRF member devices.
To collect operating statistics:
1. Disable pausing between screens of output. Skip this step if you are saving statistics to a file.
<Sysname> screen-length disable
2. Collect operating statistics for multiple feature modules.
<Sysname> display diagnostic-information
Save or display diagnostic information (Y=save, N=display)? [Y/N] :
3. At the prompt, choose to save or display operating statistics:
# To save operating statistics, enter yat the prompt and then specify the destination file path.
Save or display diagnostic information (Y=save, N=display)? [Y/N] :y
Please input the file
name(*.tar.gz)[flash:/diag_Sysname_20200101-000704.tar.gz] :flash:/diag.tar.gz

4
Diagnostic information is outputting to flash:/diag.tar.gz.
Please wait...
Save successfully.
<Sysname> dir flash:/
Directory of flash:
…
6 -rw-898180 Jun 26 2013 09:23:51 diag.tar.gz
524288 KB total (107944 KB free)
# To display operating statistics on the monitor terminal, enter nat the prompt. (The output from
this command varies by software version.)
Save or display diagnostic information (Y=save, N=display)? [Y/N] :N
===============================================
===============display clock===============
05:26:01 UTC Tue 01/01/2020
=================================================
---- More ----
4. Display the content of the operating statistics file:
# Extract and decompress the operating statistics file.
<Sysname> tar extract archive-file diag.tar.gz
Extracting archive flash:/diag.tar.gz Done.
<Sysname> gunzip diag.gz
Decompressing file flash:/diag.gz.... Done.
# Display the content of the operating statistics file.
<Sysname> more diag
===============================================
===============display clock===============
05:26:01 UTC Tue 01/01/2020
=================================================
---- More ----
Contacting technical support
If you cannot resolve an issue after using the troubleshooting procedures in this document, contact
H3C Support. When you contact an authorized H3C support representative, be prepared to provide
the following information:
•
Information described in "General guidelines."
•
Product serial numbers.
This information will help the support engineer assist you as quickly as possible.
The following is the contact information for H3C Support:
•
Telephone number—400-810-0504.
•
mailto:E-mail—[e-mail].
Troubleshooting hardware
This section provides troubleshooting information for common hardware issues.

5
NOTE:
This section describes how to troubleshoot unexpected
switch reboot, power module
failure, and fan
tray failure. To troubleshoot transceiver modules and ports, see "Troubleshooting ports."
Unexpected switch reboot
Symptom
The switch reboots unexpectedly when it is operating.
Troubleshooting flowchart
Figure 1 Troubleshooting unexpected switch reboot
Solution
To resolve the issue:
1. Verify that you can access the CLI after the switch reboots.
Unexpected switch reboot
Can you
access the CLI?
Collect operating
information Reload the system
software image
Yes
No
Resolved?
End
Contact the support
Yes No
Yes
No
Is the system software
image correct?

6
If you can access the CLI, execute the display diagnostic-information command
to collect log messages.
If you cannot access the CLI, go to step 2.
2. Verify that the system software image on the switch is correct.
Log in to the switch through the console port and restart the switch. If the system reports that a
CRC error has occurred or that no system software image is available, reload the system
software image. The system software image is automatically set to the current system software
image during the Boot ROM image running process.
3. If the issue persists, contact H3C Support.
Operating power module failure
Symptom
An operating power module fails.
Troubleshooting flowchart
Figure 2 Troubleshooting operating power module failure
Solution
To resolve the issue:
1. Identify the operating state of the power module.
<Sysname> display power
Slot 2:
Input Power: 47.0 W
PowerID State Mode Current(A) Voltage(V) Power(W) FanDirection
1 Normal AC 3.4 12.4 43.0 --
Power module
in Absent state?
Power cord
connected securely?
Remove and reinstall
the power module Resolved?
Operating power module
failure
Yes
No No
Yes
Resolved?
No Yes
Yes No
Temperature
too high?
Make sure the
temperature is in the
acceptable range Resolved?
Yes Yes
No No
Contact the support End
Connect the power
cord securely

7
2 Absent -- -- -- -- --
If the power module is in Absent state, go to step 2. If the power module is in Fault state, go to
step 3.
2. Remove and reinstall the power module to make sure the power module is installed securely.
Then, execute the display power command to verify that the power module has changed to
Normal state. If the power module remains in Absent state, replace the power module.
3. When the power module is in Fault state, perform the following tasks:
a. Verify that power is being supplied to the power module. If no power is being supplied to the
power module, supply power to it.
b. Verify that the power module surface is clean. Dust buildup might cause high temperature. If
dust is accumulated on the power module, remove the dust. Then remove and reinstall the
power module. Execute the display power command to verify that the power module has
changed to Normal state. If the power module remains in Fault state, go to step c.
c. Install the power module into an empty power module slot. Then execute the display
power command to verify that the power module has changed to Normal state in the new
slot. If the power module remains in Fault state, replace the power module.
4. If the issue persists, contact H3C Support.
Newly installed power module failure
Symptom
Anewly installed power module fails.
Troubleshooting flowchart
Figure 3 Troubleshooting newly installed power module failure
Solution
To resolve the issue:
1. Identify the operating state of the power module.
<Sysname> display power
Power module
in Absent state?
Power cord
connected securely?
Remove and reinstall
the power module Resolved?
Newly installed power
module failure
Yes
No No
Yes
Resolved?
No Yes
Yes No
Contact the support End
Connect the power
cord securely

8
Slot 2:
Input Power: 47.0 W
PowerID State Mode Current(A) Voltage(V) Power(W) FanDirection
1 Normal AC 3.4 12.4 43.0 --
2 Absent -- -- -- -- --
If the power module is in Absent state, go to step 2. If the power module is in Fault state, go to
step 3.
2. When the power module is in Absent state, perform the follow tasks:
a. Remove and reinstall the power module to make sure the power module is installed
securely. Then execute the display power command to verify that the power module has
changed to Normal state. If the power module remains in Absent state, go to step b.
b. Remove and install the power module into an empty power module slot. Then execute the
display power command to verify that the power module has changed to Normal state in
the new slot. If the power module remains in Absent state, go to step 4.
3. Remove and install the power module into an idle power module slot. Then execute the
display power command to verify that the power module has changed to Normal state in the
new slot. If the power module remains in Fault state, go to step 4.
4. If the issue persists, contact H3C Support.
Fan tray failure
Symptom
An operating fan tray or a newly installed fan tray fails.
Troubleshooting flowchart
Figure 4 Troubleshooting fan tray failure
Solution
To resolve the issue:
Fan tray
in Absent state?
Fan tray
in Fault state?
Remove and reinstall
the fan tray Resolved?
An operating or a newly
installed fan tray failure
Yes
No No
Yes
Resolved?
Yes Yes
No No
Contact the support End
Replace the fan tray

9
1. Display fan tray information.
<Sysname> display fan
Slot 2:
Fan 1:
State : Normal
Airflow Direction: Port-to-power
Prefer Airflow Direction: Port-to-power
Fan 2:
State : Normal
Airflow Direction: Port-to-power
Prefer Airflow Direction: Port-to-power
If the Airflow Direction value is different from the Prefer Airflow Direction value, replace
the fan tray with one that has an airflow direction as required, or execute the fan
prefer-direction command to configure the preferred airflow direction as required.
If the fan tray is in Absent state, go to step 2.
If the fan tray is in Fault state, go to step 3.
2. Remove and reinstall the fan tray to make sure the fan tray is installed securely. Then execute
the display fan command to verify that the fan tray has changed to Normal state. If the fan
tray remains in Absent state, replace the fan tray.
3. If the fan tray is in Fault state, perform the following tasks:
a. Execute the display environment command to display temperature information. If the
temperature continues to rise, put your hand at the air outlet vents to feel if air is being
expelled out of the air outlet.
b. If no air is being expelled out of the air outlet vents, remove and reinstall the fan tray. Then
execute the display fan command to verify that the fan tray has changed to Normal state.
If the fan tray remains in Fault state, replace the fan tray.
You must make sure the switch operating temperature is below 60°C (140°F) while you
replace the fan tray. If a new fan tray is not readily available, power off the switch to avoid
damage caused by high temperature.
4. If the issue persists, contact H3C Support.
Related commands
This section lists the commands that you might use for troubleshooting the hardware.
Command
Description
dir
Displays information about files and directories.
display boot-loader Displays
current configuration files and system software
images.
display environment
Displays temperature information.
display fan
Displays the operating states of the fan tray.
display logbuffer Displays the state of the log buffer and the log information in
the log buffer.
display power
Displays power module information.

10
Troubleshooting ACL
This section provides troubleshooting information for common issues with ACLs.
ACL application failure with an error message
Symptom
The system fails to apply a packet filter or an ACL-based QoS policy to the hardware. It also displays
the "Reason: Not enough hardware resource" message.
Troubleshooting flowchart
Figure 5 Troubleshooting an ACL application failure
Solution
To resolve the issue:
1. Execute the display qos-acl resource command, and then check the Remaining field for
ACL resources insufficiency.
If this field displays 0, the ACL hardware resources are exhausted.
2. To free hardware resources, delete unnecessary ACLs.
3. If the issue persists, contact H3C Support.
ACL application failure without an error message
Symptom
The system applies a packet filter or an ACL-based QoS policy to the hardware. However, the ACL
does not take effect.
Hardware resources
are sufficient? Delete unnecessary ACLs Resolved?
Failure to apply an ACL
Yes
No
No
Yes
Contact the support End

11
Troubleshooting flowchart
Figure 6 Troubleshooting an ACL application failure
Solution
Choose a solution depending on the module that uses the ACL.
ACL used in a QoS policy
To resolve the issue when the ACL is used in a QoS policy:
1. Verify that the QoS policy is configured correctly:
a. Use one of the following commands to check the QoS policy for configuration errors,
depending on the policy application destination:
Destination
Command
Interface
display qos policy interface
VLAN
display qos vlan-policy
Global
display qos policy global
Control plane display qos policy control-
plane
slot
slot-number
b. If the QoS policy does not contain a class-behavior association, associate the traffic
behavior with the traffic class.
c. If the QoS policy contains a class-behavior association, execute the display traffic
classifier user-defined command and the display traffic behavior
user-defined command to check for traffic class and behavior configuration errors,
respectively.
−If they are configured incorrectly, reconfigure them.
−If they are configured correctly, go to step 2.
QoS policy/packet filter
configured correctly?
ACL
configured correctly?
Reconfigure QoS
policy/packet filter Resolved?
Failure to apply an ACL
No
No
Yes
Contact the support
Resolved?
End
Reconfigure ACL Yes
No
Yes
No
Yes

12
2. Verify that the ACL is configured correctly.
Execute the display acl command to check whether the ACL is configured correctly.
If the ACL is configured incorrectly, reconfigure it.
If the ACL is configured correctly, go to step 3.
3. If the issue persists, contact H3C Support.
ACL used in a packet filter
To resolve the issue when the ACL is used in a packet filter:
1. Verify that the packet filter is configured correctly.
Execute the display packet-filter command to check whether the packet filter is
configured correctly.
If there are any configuration errors, reconfigure the packet filter.
If there is no configuration error, go to step 2.
2. Verify that the ACL is configured correctly.
Execute the display acl command to check whether the ACL is configured correctly.
If the ACL is configured incorrectly, reconfigure it.
If the ACL is configured correctly, go to step 3.
3. If the issue persists, contact H3C Support.
Packet loss or forwarding failure
Symptom
The network experiences packet loss or packet forwarding failure. You can use ACLs to count traffic
statistics to determine the location of the fault.
Troubleshooting flowchart
Figure 7 Troubleshooting a forwarding failure
Traffic forwarding failure
End
Identify traffic
characteristics
Configure a QoS policy
and apply it
Display traffic statistics,
and find the fault location

13
Solution
To resolve the issue:
1. Identify the characteristics of the packets that are not forwarded correctly.
Use a packet capture tool to identify the characteristics of the traffic, such as the IP address,
MAC address, or VLAN. Make sure the characteristics are unique among traffic to be
forwarded.
2. Configure a QoS policy and apply it to interfaces:
Figure 8 Traffic path
a. Configure a QoS policy according to the traffic characteristics. This example uses
destination IP address 2.2.2.2.
<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] time-range t1 from 12:00 11/11/2013 to 12:01 11/11/2013
[Sysname] acl number 3000 name geliACL
[Sysname-acl-adv-3000-geliACL] rule 0 permit ip destination 2.2.2.2 0 time-range
t1
[Sysname-acl-adv-3000-geliACL] quit
[Sysname] traffic classifier count
[Sysname-classifier-count] if-match acl 3000
[Sysname-classifier-count] quit
[Sysname] traffic behavior count
[Sysname-behavior-count] accounting packet
[Sysname-behavior-count] quit
[Sysname] qos policy count
[Sysname-qospolicy-count] classifier count behavior count
b. Apply the QoS policy to interfaces on devices along the forwarding path. In this example,
apply the QoS policy to the incoming traffic on GigabitEthernet 1/0/1 on Device B and
GigabitEthernet 2/0/1 on Device C.
The following shows the application on Device B:
[Sysname-qospolicy-count] quit
[Sysname] interface gigabitethernet 1/0/1
[Sysname-GigabitEthernet1/0/1] qos apply policy count inbound
3. After the time range, execute the display qos policy interface command to display
traffic statistics on the interfaces:
On GigabitEthernet 1/0/1 of Device B:
[Sysname-GigabitEthernet1/0/1] display qos policy interface gigabitethernet 1/0/1
Interface: GigabitEthernet1/0/1
Direction: Inbound
Direction: Inbound
Policy: count
Device A Device B Device C
GE1/0/1 GE2/0/1

14
Classifier: count
Operator: AND
Rule(s) : If-match ACL 3000
Behavior: count
Accounting Enable:
251 (Packets)
The output shows that a total of 251 packets match ACL 3000.
On GigabitEthernet 2/0/1 of Device C:
[Sysname-GigabitEthernet2/0/1] display qos policy interface gigabitethernet 2/0/1
Interface:GigabitEthernet2/0/1
Direction: Inbound
Direction: Inbound
Policy: count
Classifier: count
Operator: AND
Rule(s) : If-match ACL 3000
Behavior: count
Accounting Enable:
50 (Packets)
The output shows that a total of 50 packets match ACL 3000.
4. Compare the traffic statistics on the two interfaces. Packet loss or forwarding fault exists
between Device B and Device C.
Related commands
This section lists the commands that you might use for troubleshooting ACLs.
Command
Description
display acl
Displays configuration and match statistics for ACLs.
display diagnostic-information Displays operating statistics for multiple feature modules in
the system.
display packet-filter Displays whether an ACL has been successfully applied to
an interface for packet filtering.
display qos-acl resource
Displays QoS and ACL resource usage.
display qos policy control-plane Displays information about the QoS policies applied to the
specified control plane.
display qos policy global
Displays information about global QoS policies.
display qos policy interface Displays
information about the QoS policies applied to an
interface or to all interfaces.
display qos policy user-defined
Displays user-defined QoS policies.
display qos vlan-policy
Displays information about QoS policies applied to VLANs.
display traffic classifier
user-defined
Displays traffic class configuration.

15
Command
Description
display traffic behavior
user-defined
Displays traffic behavior configuration.

16
Troubleshooting IRF
This section provides troubleshooting information for common issues with IRF.
IRF fabric establishment failure
Symptom
An IRF fabric cannot be established.