Troubleshooting - Physical Connection and Interfaces(V600R003C00_02)

HUAWEI NetEngine80E/40E RouterV600R003C00

Troubleshooting - PhysicalConnection and Interfaces

Issue 02

Date 2011-09-10

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2011. All rights reserved.No part of this document may be reproduced or transmitted in any form or by any means without prior writtenconsent of Huawei Technologies Co., Ltd. Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.All other trademarks and trade names mentioned in this document are the property of their respective holders. NoticeThe purchased products, services and features are stipulated by the contract made between Huawei and thecustomer. All or part of the products, services and features described in this document may not be within thepurchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information,and recommendations in this document are provided "AS IS" without warranties, guarantees or representationsof any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in thepreparation of this document to ensure accuracy of the contents, but all statements, information, andrecommendations in this document do not constitute the warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.Address: Huawei Industrial Base

Bantian, LonggangShenzhen 518129People's Republic of China

Website: http://www.huawei.com

Email: [email protected]

Issue 02 (2011-09-10) Huawei Proprietary and ConfidentialCopyright © Huawei Technologies Co., Ltd.

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http://www.huawei.com

mailto:[email protected]

About This Document

PurposeNOTE

l This document takes interface numbers and link types of the NE40E-X8 as an example. In workingsituations, the actual interface numbers and link types may be different from those used in thisdocument.

l On NE80E/40E series excluding NE40E-X1 and NE40E-X2, line processing boards are called LineProcessing Units (LPUs) and switching fabric boards are called Switching Fabric Units (SFUs). Onthe NE40E-X1 and NE40E-X2, there are no LPUs and SFUs, and NPUs implement the same functionsof LPUs and SFUs to exchange and forward packets.

This document describes the troubleshooting workflow and methods for HUAWEINetEngine80E/40E. This document describes the troubleshooting of HUAWEI NetEngine80E/40E with various services, including information collection methods, common processing flows,common troubleshooting methods, and troubleshooting cases.

Related VersionsThe following table lists the product versions related to this document.

Product Name Version

HUAWEI NetEngine80E/40ERouter

V600R003C00

Intended AudienceThis document describes how to troubleshoot the services of the NE80E/40E device in terms ofcommon faults and causes, troubleshooting cases, and FAQs.

This document describes the procedure and method for troubleshooting for the NE80E/40Edevice.

This document is intended for:

l System maintenance engineersl Commissioning engineers

HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces About This Document


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l Network monitoring engineers

Symbol ConventionsThe symbols that may be found in this document are defined as follows.

Symbol Description

DANGERIndicates a hazard with a high level of risk, which if notavoided, will result in death or serious injury.

WARNINGIndicates a hazard with a medium or low level of risk, whichif not avoided, could result in minor or moderate injury.

CAUTIONIndicates a potentially hazardous situation, which if notavoided, could result in equipment damage, data loss,performance degradation, or unexpected results.

TIP Indicates a tip that may help you solve a problem or savetime.

NOTE Provides additional information to emphasize or supplementimportant points of the main text.

Command ConventionsThe command conventions that may be found in this document are defined as follows.

Convention Description

Boldface The keywords of a command line are in boldface.

Italic Command arguments are in italics.

[ ] Items (keywords or arguments) in brackets [ ] are optional.

{ x | y | ... } Optional items are grouped in braces and separated byvertical bars. One item is selected.

[ x | y | ... ] Optional items are grouped in brackets and separated byvertical bars. One item is selected or no item is selected.

{ x | y | ... }* Optional items are grouped in braces and separated byvertical bars. A minimum of one item or a maximum of allitems can be selected.

[ x | y | ... ]* Optional items are grouped in brackets and separated byvertical bars. Several items or no item can be selected.



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Convention Description

&<1-n> The parameter before the & sign can be repeated 1 to n times.

# A line starting with the # sign is comments.

Change HistoryChanges between document issues are cumulative. The latest document issue contains all thechanges made in earlier issues.

Changes in Issue 02 (2011-09-10)Second commercial release.There is no change relative to the previous version.

Changes in Issue 01 (2011-05-30)Initial field trial release.



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Contents

About This Document.....................................................................................................................ii

1 POS Interface Troubleshooting..................................................................................................11.1 The Physical Status of POS Interfaces Cannot Go Up.......................................................................................2

1.1.1 Common Causes........................................................................................................................................21.1.2 Troubleshooting Flowchart........................................................................................................................21.1.3 Troubleshooting Procedure........................................................................................................................31.1.4 Relevant Alarms and Logs........................................................................................................................5

1.2 Related Troubleshooting Cases..........................................................................................................................51.2.1 POS Interfaces Connecting the NE80E/40E and a Non-Huawei Device Cannot Be Up at the Link Layer............................................................................................................................................................................51.2.2 Changed MTU on a POS Interface Does Not Take Effect........................................................................71.2.3 Different C2 Values Cause Ping Failures..................................................................................................81.2.4 Inconsistent CRC Code Lengths Cause Communication Failures............................................................91.2.5 Inconsistent C2 Values and Scrambling Status Cause the NE80E/40E Unable to Receive Packets fromthe Peer.............................................................................................................................................................101.2.6 Configuring J0 and J1 When a POS Interface Is Down at the Physical Layer Causes a POS Link Unableto Go Up...........................................................................................................................................................111.2.7 Fault in the Optical Module of a POS Interface Causes Dial-up Users Unable to Open Web Pages..........................................................................................................................................................................121.2.8 A Large Number of Packets Are Dropped When Two routers Are Directly Connected by POS Interfaces..........................................................................................................................................................................131.2.9 OSPF Neighbor Relationships Cannot Be Established Because Optical Fibers Are Incorrectly Attachedto POS Interfaces..............................................................................................................................................151.2.10 Slow Internet Access Is Caused by Inconsistent Working Modes of Two Interfaces at Two Ends of aCE1 Link...........................................................................................................................................................161.2.11 Standby ATM Interface Cannot Go Up after the standby interface Command Has Been Configured onthe Active Interface..........................................................................................................................................171.2.12 Optical Module Failure Causes an Interface to Be Up and the Other Interface to Be Physically Down atTwo Ends of a Link..........................................................................................................................................18

2 Eth-Trunk Interface Troubleshooting.....................................................................................202.1 Eth-Trunk Interface Cannot Forward Traffic...................................................................................................21

2.1.1 Common Causes......................................................................................................................................212.1.2 Troubleshooting Flowchart......................................................................................................................212.1.3 Troubleshooting Procedure......................................................................................................................222.1.4 Relevant Alarms and Logs......................................................................................................................26

HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces Contents


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2.2 Related Troubleshooting Cases........................................................................................................................262.2.1 Certain Users Cannot Access the Internet by Dialing Up After a Member Interface of the Eth-TrunkInterface Becomes Faulty.................................................................................................................................26

3 GE Interface Troubleshooting..................................................................................................283.1 Related Troubleshooting Cases........................................................................................................................29

3.1.1 10GE Interfaces Connecting Two Devices Cannot Be Up......................................................................293.1.2 Interconnected Interfaces Alternate Between Up/Down States...............................................................303.1.3 Severe Packet Loss Occurs After the FE Optical Module Is Mistakenly Inserted into a GE Optical Interface..........................................................................................................................................................................313.1.4 A Device Cannot Go Up Because the 10GE WAN Board Does Not Match the Multi-mode Optical Module..........................................................................................................................................................................31

4 ATM Interface Troubleshooting..............................................................................................334.1 Two ATM Interfaces Fail to Ping Each Other.................................................................................................34

4.1.1 Common Causes......................................................................................................................................344.1.2 Troubleshooting Flowchart......................................................................................................................344.1.3 Troubleshooting Procedure......................................................................................................................354.1.4 Relevant Alarms and Logs......................................................................................................................37

HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces Contents


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1 POS Interface Troubleshooting

About This Chapter

NOTE

POS interfaces cannot be configured on the X1 and X2 models of the NE80E/40E.

1.1 The Physical Status of POS Interfaces Cannot Go Up

1.2 Related Troubleshooting Cases

HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces 1 POS Interface Troubleshooting


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1.1 The Physical Status of POS Interfaces Cannot Go Up

1.1.1 Common Causes

This fault is commonly caused by one of the following:

l Interfaces at both ends of the connection are shut down.l The optical module specification or the link is faulty.l SDH alarms exist at both ends of the connection.l The fiber is not properly connected.l The fiber is inserted into the transmit optical port/receive optical port of the optical module

on one end but is inserted into the receive optical port/transmit optical port of the opticalmodule on the other end.

l The board or the optical module is faulty.

1.1.2 Troubleshooting Flowchart

When POS interfaces of two NE80E/40Es are connected, the physical status of POS interfacescannot go Up.

The troubleshooting flowchart is as follows:l Run the command to check whether configurations of the local device are correct.l Check the fiber, optical module, and board on site.Figure Figure 1-1 shows the troubleshooting flowchart.



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Figure 1-1 Troubleshooting flowchart of the fault that the physical status of POS interfacescannot be Up

Run the undo shutdown command to

turn on interfaces.

Change the optical module or adjust the link

to ensure that the receiving or transmitting optical power is within

the normal range.

Is the fault rectified?

End

No

No

Yes

seek technical support.

No

No




No

No Is the fault rectified?

Clear SDH alarms.

Properly insert the fiber.

Insert the two ends of the fiber into correct

interfaces.

Replace the board or optical module and then

restore the link.

No Is the fault rectified?

Yes

Yes

Yes

Yes

Physical layer of the POS interface goes Down.

Are the board and optical module normal?

Are the two ends of the fiber

inserted into correct interfaces?

Is the fiber or the optical

module properly inserted?

Are SDH alarms cleared on

interfaces?

Are the receiving and transmitting optical

power on the interfaces winthin the normal

range?

Are interfaces at both ends of the connection turned

on?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

1.1.3 Troubleshooting Procedure



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ContextNOTESaving the results of each troubleshooting step is recommended. If your troubleshooting fails to correctthe fault, you will have a record of your actions to provide Huawei technical support personnel.

Procedure

Step 1 Check that interfaces at both ends of the connection are shut down, the transmit/receive opticalpower is normal, and SDH alarms exist on the interfaces at both ends of the connection.

Run the display interface pos [ interface-number ] command to check the following items:

l If the current field state is "Administratively down", it indicates that the POS interfaces areshut down. In this case, you need to run the undo shutdown command in the view of thePOS interface.

l If the transmit optical power is not within the normal range, you need to replace the opticalmodule.

l If the receive optical power falls below the receiver sensitivity of the optical module, youneed to replace the optical module or adjust the link.

l If the SDH alarm field is not "none" and the SDH error fields indicates that the number ofB1, B2, or B3 error codes increases:– The number of B1, B2, and B3 error codes increases:Check the transmission stability of

the link (including optical modules at both ends of the link) between the router and theSDH transmission device. If the direct link is a WDM link, you need to check thetransmission stability of the WDM link.

– The number of only B3 error codes increases: This problem occurs in the scenario wherethe router and the SDH transmission device are directly connected through a link. In thiscase, you need to check the transmission stability of the direct link. If the direct link is aWDM link, you need to check the transmission stability of the WDM link.

If the fault persists, go to Step 2.

Step 2 Check whether the optical modules or the fiber is properly connected.

Both the optical module and the fiber have card fasteners. If a "clap" sound is heard during theinsertion of the fiber or the optical module, it indicates that the fiber or the optical module hasbeen properly inserted.


Step 3 Check whether the two ends of the fiber are inserted into correct optical interfaces.

Remove the fiber and then change the optical interface into which one end of the fiber is inserted,for example, if the one end of the fiber is inserted into the transmit optical interface of the opticalmodule, insert it into the receive optical interface of the optical module. If the fault is rectified,it indicates that the two ends of the fiber are inserted into incorrect optical interfaces.

If the fault persists, do not change the optical interfaces into which the two ends of the fiber areinserted and go to Step 4.

Step 4 Perform the loopback test on the local fiber.

Use a fiber in good condition to connect the transmit optical interface to the receive opticalinterface of the local optical module:



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l If the physical status of the two interface goes Up, all SDH alarms on the interfaces are clearedand the number of B1, B2, or B3 error codes is not increased. It can thus be concluded thatthe board and the optical module on the local device are normal. You need to check the linkor the peer device.

l If the physical status of the two interface remains Down, it can be concluded that the boardor the optical module of the local device is faulty. You need to replace the board or the opticalmodule, or cut over services on the faulty interface to another interface that runs normally.

NOTE

When performing the loopback test on the local fiber, you need to set the clock mode of the interface as Master.


Step 5 Collect the following information and contact Huawei technical support personnel.l Results of the preceding troubleshooting procedurel Configuration files, log files, and alarm files of the devices

----End

1.1.4 Relevant Alarms and Logs

Relevant AlarmsNone.

Relevant LogsNone.


1.2.1 POS Interfaces Connecting the NE80E/40E and a Non-HuaweiDevice Cannot Be Up at the Link Layer

Fault SymptomThe NE80E/40E is connected to a non-Huawei device through an intermediate transmissiondevice. When HDLC runs on the interconnected POS interfaces, the POS interfaces are Up atthe physical layer but HDLC is Down.

Fault Analysis1. Run the display interface pos command in user view of the NE80E/40E to view the

physical layer information about the POS interface.<HUAWEI> display interface pos 1/0/0Pos1/0/0 current state : UPLine protocol current state : DOWNDescription : Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 4470 bytes, Hold timer is 10(sec)Internet Address is 1.1.1.1/24



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Link layer protocol is HDLCLCP opened, IPCP openedScramble enabled, clock master, CRC-32, loopback: noneFlag J0 "NetEngine "Flag J1 "NetEngine "Flag C2 22(0x16) SDH alarm: section layer: none line layer: none path layer: PPLM SDH error: section layer: B1 0 line layer: B2 0 REI 0 path layer: B3 0 REI 0Statistics last cleared:2006-12-20 09:20:21 Last 300 seconds input rate 0 bits/sec, 0 packets/sec Last 300 seconds output rate 0 bits/sec, 0 packets/sec Input: 24 packets, 12593 bytes Input error: 4 shortpacket, 60 longpacket, 80 CRC, 0 lostpacket Output: 604 packets, 9688 bytes Output error: 0 lostpackets Output error: 0 overrunpackets, 0 underrunpackets

2. The command output shows that B1, B2, B3, line REI, and path REI values are notincreased, which indicates that the transmission link is normal.

3. The number of longpacket, however, increases, which indicates that the scrambling modesof interfaces at both ends are different.Run the undo scramble command to disable the scrambling function. Then, longpacketstops increasing, and the interface can receive packets from the other interface. HDLC,however, is still Down.

4. The command output also shows that there is a PPLM alarm, which is generated due toinconsistency of C2 values.

NOTE

When two NE80E/40Es are interconnected, inconsistency of C2 values does not cause the physicallayer to go Down. When the NE80E/40E is connected to a non-Huawei device, however, packet lossoccurs when the C2 values of the two devices are different.

Procedure

Step 1 Run the system-view view to enter the system view.

Step 2 Run the interface interface-type interface-number command to enter the POS interface view.

Step 3 Run the flag c2 c2-value command to set the C2 value of the POS interface to that of the peerinterface. After the preceding operations, the PPLM alarm is cleared and the protocol goes Up.The fault is thus rectified.

----End

SummaryWhen the NE80E/40E is connected to a non-Huawei device, ensure that B1, B2, B3, line REI,path REI, and C2 values on both devices are the same.



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1.2.2 Changed MTU on a POS Interface Does Not Take Effect

Fault SymptomTwo routers are connected by using two POS 1/0/0 interfaces. After the MTU on POS 1/0/0 ofone router is changed to 1500 bytes by using the mtu command, the MTU does not take effect.

The following configurations of POS 1/0/0 are displayed in the display current-configurationinterface command output:

[HUAWEI] display current-configuration interface pos 1/0/0#interface Pos1/0/0 link-protocol ppp mtu 1500 undo shutdown …

The following configurations of POS 1/0/0 are displayed in the display interface pos commandoutput:

[HUAWEI] display interface pos 1/0/0Pos1/0/0 current state : UPLine protocol current state : UPLast line protocol up time : 2008-08-05 09:23:34Description:HUAWEI, Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 1492, Hold timer is 10(sec)Internet Address is 13.1.1.1/24Link layer protocol is PPP…

Fault Analysis1. Run the shutdown and undo shutdown commands on the POS interface to restart it.2. Run the display interface pos command. The effective MTU is 1492 bytes.3. Check the MTU of the peer. The MTU of the peer POS interface is 1492 bytes.

Note that during MRU negotiation, a smaller MTU between two MTUs on two ends of a PPPlink takes effect. Therefore, the 1492-byte MTU rather than the 1500-byte MTU takes effect.

Procedure

Step 1 Change the MTU of the peer POS interface to 1500 bytes and then restart the interface.After the configuration, the MTUs on both ends of the PPP link are 1500 bytes, and thus the1500-byte MTU takes effect. The fault is then rectified.

----End

SummaryDuring MRU negotiation, a smaller MTU between two MTUs on two ends of a PPP link takeseffect.



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1.2.3 Different C2 Values Cause Ping Failures

Fault Symptom

On the network shown in Figure 1-2, Router A and Router B are connected through POSinterfaces. The POS interface on Router A and the POS interface on Router B are Up at both thephysical layer and the data link layer, but the POS interfaces fail to ping each other.

Figure 1-2 Networking diagram of the case where different C2 values cause ping failures

RouterA RouterTransmissionDevice

Fault Analysis1. Run the display interface pos 1/0/0 command on Router A to check the clock mode and

whether the scrambling function is enabled.Scramble enabled, clock master, CRC-32, loopback: none

Scramble enabled in the command output indicates that the scrambling function has beenenabled on Router A. The display interface pos 1/0/0 command output on Router B showsthat the scrambling function has also been enabled.clock master in the command output indicates that the clock mode is master. In addition,it is confirmed that the clock mode of the peer is slave, which means the clock modesconfigured on the two devices are correct.

2. Run the display pos interface pos 1/0/0 command on Router A to check the overhead byteconfigured for this interface.

SDH OverHead: Rx C2 Value:0xff, Tx C2 Value:0x16

The command output shows that the C2 values configured for the transmitting end and thereceiving end are different and therefore the receiving end fails to forward packets. Theping fails.

Procedure

Step 1 Run the system-view command on Router A to enter the system view.

Step 2 Run the interface pos 1/0/0 command on Router A to enter the POS interface view.

Step 3 Run the flag c2 c2-value command on Router A to set the C2 value of the POS interface to thesame as that of the POS interface on Router B.

After the operations, the two ends are configured with the same C2 value, and thus they can pingeach other successfully. The fault is rectified.

----End



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Summary

When using POS interfaces to connect two devices, ensure that the two interfaces are configuredwith the same overhead byte; both are enabled or disabled with the scrambling function; one isconfigured with the master clock mode and the other is configured with the slave clock mode.

1.2.4 Inconsistent CRC Code Lengths Cause CommunicationFailures

Fault Symptom

On the current network, the NE80E/40E is connected to a non-Huawei device through a POSinterface. The display interface pos 1/0/0 command is run in the POS interface view. The POSinterface is Up at the physical layer but is Down at the data link layer.

Pos1/0/0 current state : UPLine protocol current state : DOWN

Fault Analysis1. Run the display interface pos 1/0/0 command on the router. The result shows that the data

link protocol of the POS interface is PPP, which is the same as the data link protocol of thepeer.Pos1/0/0 current state : UPLine protocol current state : DOWNDescription : Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 4470 bytes, Hold timer is 10(sec)Internet Address is 1.1.1.1/24Link layer protocol is PPPLCP opened, IPCP openedThe Vendor Name is FINISAR CORP. , The Vendor PN is FTLF1321P1BTL-HWTransceiver BW: 2.5G, Transceiver Mode: Single ModeWaveLength: 1310nm, Transmission Distance: 2kmRx Power: -12.29dBm, normal range: [-23.97, 0.75]dBmTx Power: -5.43dBm, normal range: [-13.49, 1.00]dBmPhysical layer is Packet Over SDH,Scramble enabled, clock master, CRC-32, loopback: none

The preceding information shows that the CRC code length configured for the POSinterface is 32 bits, different from the CRC code length (16 bits) configured on the peerPOS interface. This causes the POS interface on the router to fail to communicate with thePOS interface on the peer device.

Procedure

Step 1 Run the system-view command on the router to enter the system view.

Step 2 Run the interface pos 1/0/0 command on the router to enter the POS interface view.

Step 3 Run the crc 16 command on the router to change the CRC code length of the POS interface to16 bits.

After the operations, run the display interface pos 1/0/0 command on the router to check theinterface status. The interface is Up at both the physical layer and the data link layer. The faultis rectified.

----End



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SummaryA POS interface can be configured with either 16-bit CRC or 32-bit CRC. When using POSinterfaces to connect devices, ensure that the two interfaces are configured with the same CRCcode length. Otherwise, communication will fail.

1.2.5 Inconsistent C2 Values and Scrambling Status Cause theNE80E/40E Unable to Receive Packets from the Peer

Fault SymptomOn the network shown in Figure 1-3, Router A is connected to Router B and Router C throughan optical splitter over POS links. After the configuration, Router C can receive packets fromRouter A but B cannot.

Figure 1-3 Networking diagram of the case where the NE80E/40E cannot receive packets fromthe peer

OpticalSplitter

RouterA

RouterC

RouterB

Fault Analysis1. Remove the optical fiber connecting the optical splitter to Router C and insert the fiber into

Router B. Router B still cannot receive packets from Router A, excluding the possibilitythat the fault is caused by the optical splitter and optical fiber.

2. Replace the optical module inserted into the POS interface on Router B. The fault persists,excluding the possibility that the fault is caused by this optical module.

3. Run the display interface pos 1/0/0 command on Router B. The POS interface onRouter B is Up at both the physical layer and the data link layer. In addition, the data linkprotocol is HDLC, which is the same as the data link protocol of the peer.Pos1/0/0 current state : UPLine protocol current state : UPDescription : Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 4470 bytes, Hold timer is 10(sec)Internet Address is 1.1.1.1/24Link layer protocol is HDLCLCP opened, IPCP openedThe Vendor Name is FINISAR CORP. , The Vendor PN is FTLF1321P1BTL-HWTransceiver BW: 2.5G, Transceiver Mode: Single ModeWaveLength: 1310nm, Transmission Distance: 2kmRx Power: -32.29dBm, normal range: [-23.97, 0.75]dBmTx Power: -5.43dBm, normal range: [-13.49, 1.00]dBmPhysical layer is Packet Over SDH,



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Scramble enabled, clock master, CRC-32, loopback: noneFlag J0 "NetEngine "Flag J1 "NetEngine "Flag C2 22(0x16)

The preceding information shows that the C2 value of Router B is 22, which is differentfrom the C2 value (16) of Router A. Additionally, Router B is enabled with the scramblingfunction but Router A is disabled with the scrambling function. It is concluded thatinconsistent configurations of POS interfaces on Router A and Router B cause Router Bunable to receive packets from Router A.

Procedure

Step 1 Run the system-view command on Router B to enter the system view.

Step 2 Run the interface pos 1/0/0 command on Router B to enter the POS interface view.

Step 3 Run the flag c2 16 command to change the C2 value of the POS interface to 16, which is thesame as the C2 value of the POS interface on Router A.

Step 4 Run the undo scramble command on Router B to disable the scrambling function.

After the operations, Router B can receive packets from Router A. The fault is rectified.

----End

Summary

Before two devices communicate with each other, ensure that the default settings of the two endsare the same, preventing communication failures. Otherwise, the link will go Down, and thusservices cannot be transmitted.

1.2.6 Configuring J0 and J1 When a POS Interface Is Down at thePhysical Layer Causes a POS Link Unable to Go Up

Context

On the live network, the NE80E/40E is connected to a non-Huawei device through a POSinterface. The POS interface needs to be configured with the flag j0 peer and flag j1 peercommands so that the POS interface can learn the corresponding parameters configured on thepeer. The display interface pos 1/0/0 command is used in the view of the POS interface on theNE80E/40E. The POS interface is Up at the physical layer but is Down at the data link layer.

Pos1/0/0 current state : UPLine protocol current state : DOWN

Fault Analysis

Default settings of devices of different vendors are probably different. Therefore, when theNE80E/40E is connected to a non-Huawei device, you need to configure J0 and J1 to learn thecorresponding parameters configured on the peer. If the flag j0 peer and flag j1 peer commandsare run when the interface is Down at the physical layer, generated parameters are not learnedfrom the peer and no parameter negotiation is performed even if this interface goes Up at thephysical layer. As a result, parameter negotiation between the two POS interfaces fails, and thusthe POS interface cannot go Up at the data link layer.



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Procedure

Step 1 Run the display interface pos 1/0/0 command on the NE80E/40E to check whether the POSinterface is Up at the physical layer. If the interface is Down at the physical layer, you need torectify the physical layer fault before performing the following operations.

Step 2 Run the interface pos 1/0/0 command on the NE80E/40E to enter the POS interface view.

Step 3 Run the undo flag command on the NE80E/40E to delete the configuration of the SDH overheadbyte.

Step 4 Run the display interface pos 1/0/0 command on the NE80E/40E to check whether the POSinterface is physically Up. If the physical status of the POS interface is Down, rectify the faultat the physical layer, and perform the following configurations.

Step 5 Run the flag j0 peer and flag j1 peer commands on the NE80E/40E to configure SDH overheadbytes.

After the operations, run the display interface pos 1/0/0 command on the router to check theinterface status. The interface is Up at both the physical layer and the data link layer. The faultis rectified.

----End

SummaryBefore using the flag j0 peer and flag j1 peer commands to learn J0 and J1 values configuredon the peer, ensure that the interface is Up at the physical layer.

1.2.7 Fault in the Optical Module of a POS Interface Causes Dial-up Users Unable to Open Web Pages

Fault SymptomOn the network shown in Figure 1-4, the router is connected to a BRAS through a POS interface.Dial-up users attached to the BRAS access the Internet through the router. After theconfiguration, dial-up users cannot open Web pages.

Figure 1-4 Networking diagram of the case where a fault in the optical module of a POS interfacecauses dial-up users unable to open Web pages

PC BRAS Router

Fault Analysis1. Run the display interface pos 1/0/0 command on the router to check the configuration of

the POS interface.Pos1/0/0 current state : UPLine protocol current state : UP



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Description:HUAWEI, Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 1024, Hold timer is 10(sec)

The command output shows that the MTU of the POS interface connecting the router tothe BRAS is 1024 bytes, but the MTU of the directly-connected POS interface on the BRASis 1500 bytes. The MTU values of the two POS interfaces are unmatched.

2. On the POS interface of the router, use an optical fiber to connect the transmitter to thereceiver. Run the mtu 1500 command to change the MTU to 1500 bytes. Run the displayinterface pos 1/0/0 command. The MTU of the POS interface on the router is still 1024bytes, indicating that the SFP optical module of the POS interface is faulty.

Procedure

Step 1 Replace the optical module of the POS interface on the router.

Step 2 Run the display interface pos 1/0/0 command on the router. The MTU value of the local POSinterface is the same as the MTU value of the peer POS interface, and the local interface is Up.

After the operations, dial-up users attached to the BRAS can open Web pages. The fault isrectified.

----End

SummaryBefore using POS interfaces to communicate, create a self-loop to check whether parameters ofthe two interfaces are the same. Services can be processed only when the parameters configuredon the two ends of a link are the same.

1.2.8 A Large Number of Packets Are Dropped When Two routersAre Directly Connected by POS Interfaces

Fault SymptomOn the network shown in Figure 1-5, a POS interface of Router A is directly connected to aPOS interface of Router B through an optical fiber. After Router A pings Router B, a largenumber of packets are dropped. After Router B pings Router A, no packet is dropped but thenumber of incorrect packets is large keeps increasing on the POS interface of Router B.

Figure 1-5 Networking diagram of the case where a large number of packets are dropped whentwo routers are directly connected by POS interfaces

RouterA RouterB

Fault Analysis1. Run the display interface pos 1/0/0 command on Router A to check information about the

POS interface.



13

Pos1/0/0 current state : UPLine protocol current state : UPDescription:HUAWEI, Pos1/0/0 InterfaceRoute Port,The Maximum Transmit Unit is 4470, Hold timer is 10(sec)Internet protocol processing : enabledLink layer protocol is HDLCLCP openedThe Vendor PN is FTRJ8519P1BNL-HWThe Vendor Name is FINISAR CORP.Port BW: 2.5G, Transceiver max BW: 1G, Transceiver Mode: MultiModeWaveLength: 850nm, Transmission Distance: 550mRx Power: -12.29dBm, normal range: [-23.97, 0.75]dBmTx Power: -5.43dBm, normal range: [-13.49, 1.00]dBmPhysical layer is Packet Over SDHScramble enabled, clock slave, CRC-32, loopback: noneFlag J0 "NetEngine "Flag J1 "NetEngine "Flag C2 22(0x16) SDH alarm: section layer: none line layer: none path layer: none SDH error: section layer: B1 3554 line layer: B2 689530 REI 113076 path layer: B3 28473 REI 4Statistics last cleared:never Last 300 seconds input rate 8 bits/sec, 0 packets/sec Last 300 seconds output rate 80 bits/sec, 0 packets/sec Input: 8736 packets, 25483760 bytes Input error: 6 shortpacket, 1 longpacket, 88 CRC, 0 lostpacket Output: 14510 packets, 928640 bytes Output error: 0 lostpackets Output error: 0 overrunpackets, 0 underrunpackets Input bandwidth utilization : 0.01% Output bandwidth utilization : 0.01%

Based on the comparison of the command output and the configuration information aboutRouter B. The encapsulation modes (HDLC) and intervals (10s) set on Router A andRouter B are the same. The configurations are correct.

2. In addition, the clock modes of the POS interfaces on Router B and Router A are slave.The problem occurs because no master clock is configured on either of routers connectedby the optical fiber.

Procedure


Step 2 Run the interface pos 1/0/0 command to enter the POS interface view.

Step 3 Run the clock master command to set the clock mode of the POS interface to Master.

After the preceding operations, on Router A, ping Router B. No packet is dropped. The fault isthen rectified.

----End

SummaryIn the case that the POS interfaces of both Router A and Router B are configured with the slaveclock mode, and no transmission device functioning as a master clock to provide clock signalsfor Router A or Router B, one of POS interfaces on Router A and Router B must be configuredwith the master clock mode so that services can be forwarded properly.



14

1.2.9 OSPF Neighbor Relationships Cannot Be Established BecauseOptical Fibers Are Incorrectly Attached to POS Interfaces

Fault Symptom

On the network shown in Figure 1-6, Router B is connected to Router A through a 155M POSlink and Router B is connected to Router C through a 155M POS link. The connected interfacesare configured with PPP at the data link layer and OSPF at the network layer. After theconfiguration, no traffic is transmitted on either of the two links. Router B can successfully pingRouter A and Router C. The display ospf peer command output shows that the State fielddisplays Init, indicating that the OSPF neighbor relationships are in Init state.

OSPF Process 1 with Router ID 10.1.1.2 Neighbors Area 0.0.0.0 interface 10.1.1.2(Pos1/0/0)'s neighbors Router ID: 10.1.1.1 Address: 10.1.1.1 GR State: Normal State: Init Mode:Nbr is Slave Priority: 1 DR: 10.1.1.1 BDR: None MTU: 0 Dead timer due in 35 sec Retrans timer interval: 5 Neighbor is up for 00:00:05 Authentication Sequence: [ 0 ]

Figure 1-6 Networking diagram of the case where the OSPF neighbor relationships cannot beestablished because optical fibers are incorrectly attached to POS interfaces

RouterA RouterB RouterC

POS1/0/0POS1/0/0

POS2/0/0

POS2/0/0

Fault Analysis1. Run the display current-configuration configuration ospf command on each Router to

check OSPF configurations. The configurations are correct.

2. Run the display interface pos interface-number command on the POS interface of eachRouter to check the MTU. MTUs on all POS interfaces are 1526 bytes. The problem is notcaused by the inconsistent MTUs at two ends of each link.

3. Run the display this command in the POS interface view on each Router. The IP addressof POS 1/0/0 on Router A is 10.1.2.1/24; the IP address of POS 1/0/0 on Router B is10.1.1.2/24; the IP address of POS 2/0/0 on Router B is 10.1.2.2/24; the IP address of POS2/0/0 on Router C is 10.1.1.1/24. The command output shows that the IP addresses of twointerfaces that should have been in the same network segment are not in the same segment.This indicates that the optical fibers have been interchanged.

Procedure

Step 1 Interchange the optical fibers attached to the POS interfaces on Router B.



15

After the preceding operations, run the display ospf peer command to check the OSPF neighborstatus. The State field displays Full. The fault is rectified.

----End

SummaryPPP does not check the peer IP address during negotiation although the IP addresses of connectedinterfaces are in different network segments, and the two devices can successfully ping eachother. Ensure that IP addresses of interfaces at both ends of a PPP link are in the same networksegment and the optical fibers are not interchanged during the configuration of a PPP link.

1.2.10 Slow Internet Access Is Caused by Inconsistent WorkingModes of Two Interfaces at Two Ends of a CE1 Link

Fault SymptomOn the network shown in Figure 1-7, Router A and Router B are connected by a CE1 link. Thelink bandwidth is set to 2 Mbit/s. After the configuration, the transmission delay is in anacceptable range when there is no traffic on the CE1 interface on Router A, but the transmissiondelay increases to over 300s when there is traffic. Users attached to Router A access the Internetat low speeds.

Figure 1-7 Networking diagram of the case where slow Internet access is caused by inconsistentworking modes of two interfaces at two ends of a CE1 link

RouterA RouterB

PC1

PC2

CE11/0/0

Fault Analysis1. Run the display this interface command in the CE1 interface view of Router A. The

maximum bandwidth of the interface is only 500 Mbit/s. The traffic volume is small andthus does not cause slow Internet access.

2. Run the display controller e1 command on Router A. The frame format on the CE1interface is crc4, but the frame format on the CE1 interface of Router B is no-crc4. Thesedifferent settings cause slow Internet access.E1 1/0/0 current state : UPDescription : E1 1/0/0 Interface



16

Physical layer is Packet Over CRC4clock master, linecode hdb3 , loopback nonesection layer: alarm: LOSline layer: alarm: nonepath layer: alarm: none

Procedure


Step 2 Run the controller e1 1/0/0 command on Router A to enter the CE1 interface view.

Step 3 Run the frame-format no-crc4 command on Router A to change the frame format to no-crc4.

After the preceding operations, the frame formats of both Routers are no-crc4. Users attachedto Router A access to the Internet at normal speeds. The fault is rectified.

----End

SummaryServices are properly processed only when the frame formats configured on interfaces at the twoends of a CE1 link are the same.

1.2.11 Standby ATM Interface Cannot Go Up after the standbyinterface Command Has Been Configured on the Active Interface

Fault SymptomThe router accesses an ATM network shown in Figure 1-8 through an ATM switch. Therouter is connected to the ATM switch through an active link and a standby link. The activeinterface is Serial 1/0/0 and its bandwidth is 2 Mbit/s. The standby interface is ATM 2/0/0 andits bandwidth is 155 Mbit/s. The active link is connected and the standby link is removed. Afterthe active link fails, the standby link is connected. The standby ATM interface cannot go Up.

Figure 1-8 Networking diagram of the case where the standby ATM interface cannot go Upafter the standby interface command has been configured on the active interface

Serial1/0/0

ATM2/0/0Router Switch

ATM network

Fault Analysis1. Run the display this command in the view of Serial 1/0/0 on the router. The standby

interface ATM2/0/0 command has been configured to use ATM 2/0/0 as a backup forSerial 1/0/0.



17

When both the active link and standby link are connected, the standby interface goes Upat the data link layer if the active interface goes Down at the data link layer. If the standbylink is disconnected at the physical layer when the active link works properly and then isreconnected after the active link fails, the backup function cannot take effect and thus ATM2/0/0 cannot go Up at the data link layer.

ProcedureStep 1 Run the system-view command to enter the system view.

Step 2 Run the interface serial1/0/0 command to enter the serial interface view.

Step 3 Run the undo standby interface atm2/0/0 command to disable the ATM interface from servingas the standby interface.

After the preceding operations, ATM 2/0/0 goes Up at the data link layer. The fault is rectified.

----End

SummaryEnsure that the standby interface is Up at the data link layer during the configuration of interfacebackup; otherwise, the standby interface cannot work after the active interface fails.

1.2.12 Optical Module Failure Causes an Interface to Be Up and theOther Interface to Be Physically Down at Two Ends of a Link

ContextTwo routers are connected by using a multi-mode optical fiber. After a period of operation, theindicator on router A is On but the physical status on the interface of router B is Down, indicatingthat the link is disconnected.

Fault Analysis1. Run the display this command in the interface view on Router B. The interface is not

configured with the shutdown or loopback command.2. Run the shutdown command on the interface of Router B. The physical status of the

interface on Router A is Down. This indicates that the optical fiber is correctly connected.3. Remove the optical module from the interface and then insert it to another interface on

Router B. The problem persists, indicating that the optical module fails.

ProcedureStep 1 Replace the optical module on Router B.

After the preceding operation, the link status becomes Up at both ends of the link. The fault isrectified.

----End

SummaryThe indicator on Router A is On, only indicating that Router A has received signals fromRouter B. Without the help of an optical power meter, replace the optical module at one end and



18

then at the other end to check whether the RX port or the TX port becomes faulty in the casethat the optical fiber works properly.



19

2 Eth-Trunk Interface Troubleshooting

About This Chapter

2.1 Eth-Trunk Interface Cannot Forward Traffic


HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces 2 Eth-Trunk Interface Troubleshooting


20

2.1 Eth-Trunk Interface Cannot Forward Traffic

2.1.1 Common CausesAfter an Eth-Trunk interface is configured, it cannot forward traffic.

This fault is commonly caused by one of the following:l Eth-Trunk member interfaces are faulty.l Configurations of Eth-Trunk member interfaces on the two ends are inconsistent.l The number of Up Eth-Trunk member interfaces is smaller than the lower threshold.l Negotiation between member interfaces of the Eth-Trunk interface in static LACP mode

fails.l BFD, which is used to detect an Eth-Trunk member interface, is incorrectly configured.

2.1.2 Troubleshooting FlowchartOn the network shown in Figure 2-1, the Eth-Trunk interface cannot forward traffic.

Figure 2-1 Networking diagram of Eth-Trunk interfaces

RouterA RouterBGE1/0/1GE1/0/2

Eth-Trunk1 Eth-Trunk1

GE1/0/3

GE1/0/1GE1/0/2GE1/0/3

The troubleshooting roadmap is as follows:l Check that Eth-Trunk member interfaces work properly.l Check information about Eth-Trunk member interfaces on both ends.l Check that the number of Up member interfaces is greater than the configured lower

threshold.l Check that LACP negotiation succeeds if the Eth-Trunk interface is in static LACP mode.l Check that BFD configurations are correct if BFD is configured to track the status of an

Eth-Trunk member interface.

Figure 2-2 shows the troubleshooting flowchart.



21

Figure 2-2 Troubleshooting flowchart for the fault that the Eth-Trunk interface cannot forwardtraffic

Eth-Trunk member interfaces

work properly?

Member interfaces on both ends

are consistent?

Number of Up member interfaces

is below the lower threshold?

Negotiation between Eth-Trunk

interfaces working in static LACP mode

fails?

Collect information

Check physical links connecting member interfaces and rectify

the link fault

Change the lower threshold

Locate the cause of the negotiation failure and

modify the configuration

Modify the configuration

Eth-Trunk interface cannot forward traffic

Yes

No

Seek technical support

No

End

Is fault rectified?

Is fault rectified?

Is fault rectified?

Is fault rectified?

Yes

Yes

Yes

Yes

Yes

No

No

No

No

BFD is configured to track

the status of an Eth-Trunk member

interface?

Check and modify BFD configurations Is fault rectified?

Yes

No

Yes

No

Yes

No

Yes

No

2.1.3 Troubleshooting ProcedureNOTE

Saving the results of each troubleshooting step is recommended. If your troubleshooting fails to correctthe fault, you will have a record of your actions to provide Huawei technical support personnel.



22

Procedure

Step 1 Check that Eth-Trunk member interfaces work properly.

Run the display eth-trunk 1 command in any view to check the status of the Eth-Trunk interface.

[HUAWEI] display eth-trunk 1Eth-Trunk1's state information is:WorkingMode: NORMAL Hash arithmetic: According to flowLeast Active-linknumber: 1 Max Bandwidth-affected-linknumber: 16Operate status: down Number Of Up Port In Trunk: 0--------------------------------------------------------------------------------PortName Status WeightGigabitEthernet1/0/1 Down 1GigabitEthernet1/0/2 Down 1GigabitEthernet1/0/3 Down 1l If a member interface is Down, you need to troubleshoot the physical interface. For detailed

troubleshooting procedures, see "Physical Interconnection Troubleshooting".l If all member interfaces are Up, go to Step 2.

Step 2 Check information about Eth-Trunk member interfaces on both ends.l Check information about member interfaces of the Eth-Trunk interface on Router A.

[RouterA] display eth-trunk 1Eth-Trunk1's state information is:WorkingMode: NORMAL Hash arithmetic: According to flowLeast Active-linknumber: 1 Max Bandwidth-affected-linknumber: 16Operate status: up Number Of Up Port In Trunk: 3--------------------------------------------------------------------------------PortName Status WeightGigabitEthernet1/0/1 Up 1GigabitEthernet1/0/2 Up 1GigabitEthernet1/0/3 Up 1

l Check information about member interfaces of the Eth-Trunk interface on Router B.[RouterB] display eth-trunk 1Eth-Trunk1's state information is:WorkingMode: NORMAL Hash arithmetic: According to flowLeast Active-linknumber: 4 Max Bandwidth-affected-linknumber: 16Operate status: up Number Of Up Port In Trunk: 2--------------------------------------------------------------------------------PortName Status WeightGigabitEthernet1/0/1 Up 1GigabitEthernet1/0/2 Up 1

l If the number of member interfaces of the Eth-Trunk interface on Router A is differentfrom that on Router B, add the required physical interfaces to the Eth-Trunk interface.

l If the number of member interfaces of the Eth-Trunk interface on Router A is the same asthat on Router B, go to Step 3.

Step 3 Check whether the Eth-Trunk interface is configured with a lower threshold of Up memberinterfaces.

Run the display eth-trunk 1 command on Router A and Router B to view the configuration ofthe Eth-Trunk interface.

[RouterA] display eth-trunk 1Eth-Trunk1's state information is:WorkingMode: NORMAL Hash arithmetic: According to flowLeast Active-linknumber: 4 Max Bandwidth-affected-linknumber: 16Operate status: down Number Of Up Port In Trunk: 3--------------------------------------------------------------------------------PortName Status Weight



23

GigabitEthernet1/0/1 Up 1GigabitEthernet1/0/2 Up 1GigabitEthernet1/0/3 Up 1

The preceding command output shows that the lower threshold of Up member interfaces of theEth-Trunk interface has been set to 4. However, the number of Up member interfaces of the Eth-Trunk interface is actually 3, which causes the Eth-Trunk interface to go Down.

l If the Eth-Trunk interface is configured with a lower threshold of Up member interfacesand the configured lower threshold is greater than the actual number of Up memberinterfaces, set the lower threshold to a proper value.

l If the Eth-Trunk interface is not configured with a lower threshold of Up member interfaces,go to Step 4.

Step 4 Check whether Eth-Trunk interfaces work in static LACP mode.

Run the display eth-trunk 1 command on Router A and Router B to view the configuration ofthe Eth-Trunk interface.[RouterA] display eth-trunk 1Eth-Trunk1's state information is:Local:LAG ID: 1 WorkingMode: STATICPreempt Delay: Disabled Hash arithmetic: According to flowSystem Priority: 32768 System ID: 0018-826f-fc7aLeast Active-linknumber: 1 Max Active-linknumber: 16Operate status: down Number Of Up Port In Trunk: 0--------------------------------------------------------------------------------ActorPortName Status PortType PortPri PortNo PortKey PortState WeightGigabitEthernet1/0/1 Unselect 1GE 32768 264 305 11100010 1GigabitEthernet1/0/2 Unselect 1GE 32768 265 305 11100010 1GigabitEthernet1/0/3 Unselect 1GE 32768 266 305 11100011 1

Partner:--------------------------------------------------------------------------------ActorPortName SysPri SystemID PortPri PortNo PortKey PortStateGigabitEthernet1/0/1 0 0000-0000-0000 0 0 0 11100011GigabitEthernet1/0/2 0 0000-0000-0000 0 0 0 11100011GigabitEthernet1/0/3 0 0000-0000-0000 0 0 0 11100011l If the Eth-Trunk interface is configured to work in static LACP mode and no physical

interface is selected, it indicates that LACP negotiation is unsuccessful. Possible causes forunsuccessful LACP negotiation are as follows:– Member interfaces fail, causing timeout of LACP protocol packets.

In this case, you need to troubleshoot member interfaces.– The Eth-Trunk interface on one end is configured to work in static LACP mode, whereas

the Eth-Trunk interface on the other end is not.Correct the configurations of the two ends of the Eth-Trunk link to make themconsistent.

After the configurations are corrected and LACP negotiation succeeds, the output of thedisplay eth-trunk 1 command is as follows:[RouterB] display eth-trunk 1Eth-Trunk1's state information is:Local:LAG ID: 1 WorkingMode: STATICPreempt Delay: Disabled Hash arithmetic: According to flowSystem Priority: 32768 System ID: 0018-826f-fc7aLeast Active-linknumber: 1 Max Active-linknumber: 16Operate status: up Number Of Up Port In Trunk: 3--------------------------------------------------------------------------------ActorPortName Status PortType PortPri PortNo PortKey PortState



24

WeightGigabitEthernet1/0/1 Selected 1GE 32768 264 305 11111100 1GigabitEthernet1/0/2 Selected 1GE 32768 265 305 11111100 1GigabitEthernet1/0/3 Selected 1GE 32768 266 305 11111100 1

Partner:--------------------------------------------------------------------------------ActorPortName SysPri SystemID PortPri PortNo PortKey PortStateGigabitEthernet1/0/1 32768 0018-823c-c473 32768 2056 305 11111100GigabitEthernet1/0/2 32768 0018-823c-c473 32768 2057 305 11111100GigabitEthernet1/0/3 32768 0018-823c-c473 32768 2058 305 11111100

If LACP negotiation fails after the configurations are corrected, go to Step 5.

l If the Eth-Trunk interface is not configured to work in static LACP mode, go to Step 5.

Step 5 Check whether BFD is configured to track the status of an Eth-Trunk member interface.Run the display current-configuration command to view the configuration files of the devicesat the two ends of the Eth-Trunk link to check whether BFD is configured to track the status ofan Eth-Trunk member interface.

l If a device is configured with bfd Eth-Trunk bind peer-ip default-ip interfacegigabitethernet 1/0/1, it indicates that the device has been configured with BFD to trackthe status of an Eth-Trunk member interface.

If the BFD configuration is modified but the commit command is not used, the memberinterface of the Eth-Trunk interface will go Down. The output of the display interfaceinterface-type interface-number command in the interface view shows that this memberinterface is Up.

For detailed information about BFD configurations, see the chapter "BFD Configuration"in the NE80E/40E Configuration Guide - Reliability.

l If no device is configured with BFD to track the status of Eth-Trunk member interfaces,go to Step 6.

Step 6 Collect the following information and contact Huawei technical support personnel.

CAUTIONDebugging affects the system performance. Therefore, after debugging, run the undo debuggingall command to disable it immediately.

l Results of the preceding troubleshooting procedure

l Configuration files, log files, and alarm files of the devices

l display interface interface-type interface-numberl display eth-trunk [ trunk-id [ interface interface-type interface-number | verbose ] ]

l debugging trunk lagmsg slot slot-idl debugging trunk lagmsgl debugging trunk state-machinel debugging trunk lacp-pdu slot slot-idl debugging trunk lacp-pdul terminal debugging



25

l terminal monitor

----End

2.1.4 Relevant Alarms and LogsNone.


2.2.1 Certain Users Cannot Access the Internet by Dialing Up Aftera Member Interface of the Eth-Trunk Interface Becomes Faulty

Fault Symptom

As shown in Figure 2-3, the NE80E/40E is connected to the authentication server through anEth-Trunk. Certain PPPoE users attached to the NE80E/40E cannot access the Internet by dialingup. These users are widely distributed and do not reside in one physical area.

Figure 2-3 Networking diagram of user access

Dial-up user 1

DSLAM Router Server

Dial-up user 2

Dial-up user 3

Eth-Trunk

Fault Analysis1. Check the MAC addresses of the users where faults occur. The result shows that these MAC

addresses are widely distributed and do not have common characteristics. Therefore, it canbe inferred that the NE80E/40E or the authentication server is not configured withrestrictions on these users.

2. Run the ping command to check the connectivity of each link between the user and theauthentication server. The result shows that packet loss occurs on the link connecting theNE80E/40E and the authentication server.



26

3. Run the display interface interface-type interface-number command on the NE80E/40Eto check the status of each member interface.The result shows that one member interface cannot forward data although the interface isUp at the physical and link layers.

Load balancing is implemented on member interfaces of an Eth-Trunk interface based on theHash algorithm. Therefore, once a member interface is faulty, the traffic on the faulty interfacecannot be forwarded.

Procedure

Step 1 Run the shutdown command on the interface of the faulty link to shut down the link so that theEth-Trunk can sense the link fault.

Step 2 Replace the faulty link between the NE80E/40E and the authentication server.After the preceding operations, users can normally access the Internet by dialing up. The faultis rectified.

----End

Summaryl When users in different physical areas cannot access the Internet, check whether these users

have common characteristics, for example, whether their MAC addresses are close to eachother. If so, do as follows:– Check whether the link connecting the user is faulty.– Check whether a specific policy is configured on the NE80E/40E or the authentication

server to restrict users.l When users that reside in different areas cannot access the Internet, check whether there is

a Trunk. If so, check the status of member interfaces. If a member interface is faulty, thetraffic on the faulty interface cannot be forwarded.



27

3 GE Interface Troubleshooting

About This Chapter


HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces 3 GE Interface Troubleshooting


28


3.1.1 10GE Interfaces Connecting Two Devices Cannot Be Up

Fault Symptom

When two NE80E/40Es are connected through 10GE interfaces, the interfaces cannot be Up.

Fault Analysis1. Run the display interface GigabitEthernet 1/0/0 command in the system view to view

interface information.GigabitEthernet1/0/0 current state : DOWNLine protocol current state : DOWNDescription:TO[HUAWEI-A1]-10G-14/0/0Route Port,The Maximum Transmit Unit is 1500IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 0018-82b1-7c2dThe Transceiver Vendor Name is FINISAR CORP.The Transceiver Vendor PN is FTLX1412M3BCLBW: 10G, Transceiver Mode: SingleModeWaveLength: 1310nm, Transmission Distance: 10kmRx Power: -12.29dBm, normal range: [-23.97, 0.75]dBmTx Power: -5.43dBm, normal range: [-13.49, 1.00]dBm

The receiving optical power and transmitting optical power displayed through the RxPower and Tx Power items respectively are both in the normal range, which indicates thatthe fault is not caused by optical power.

2. Replace the optical fiber. The fault persists, which indicates that the fault is not caused bythe optical fiber.

3. Replace the optical module. The fault persists, which indicates that the fault is not causedby the optical module.

4. Check the boards on the two interconnected devices. It is found that the 10GE interface onthe local device is in the LAN transmission mode whereas the 10GE interface on the remotedevice is in the WAN transmission mode. Therefore, it can be inferred that the 10GEinterfaces cannot be Up because their transmission modes do not match.

Procedure

Step 1 Run the system-view command to enter the system view.

Step 2 Run the interface interface-type interface-number command to enter the interface view.

Step 3 Run the set transfer-mode wan command to set the transmission mode of the interface to WANso that the transmission modes of the two interfaces can match.

----End

Summary

When two interfaces are connected through 10GE interfaces whereas the 10GE interfaces cannotbe Up, you can check the following items to rectify the fault:



29

1. Optical power2. Optical fiber3. Optical module4. Transmission modes of the two interconnected interfaces

10GE interfaces can work in either WAN or LAN transmission mode. In different modes,physical frames are encapsulated in different manners. Therefore, a 10GE interface working inWAN transmission mode cannot communicate with a 10GE interface working in LANtransmission mode. In this case, when the two devices are connected through 10GE interfaces,ensure that their transmission modes are the same.

3.1.2 Interconnected Interfaces Alternate Between Up/Down States

Fault Symptom

Two devices are directly connected through GE interfaces by optical fibers. The GE interfaces,however,alternate between Up/Down states. The following log messages are displayed:

%Nov 12 11:00:10 2007 HUAWEI PHY/2/PHY:Slot=2;GigabitEthernet2/0/0: change status to down%Nov 12 11:00:11 2007 HUAWEI PHY/2/PHY:Slot=2;GigabitEthernet2/0/0: change status to up

Fault Analysis1. Run the display interface [ interface-type interface-number ] command in any view on the

two interconnected interfaces, and you can find that both interfaces receive CRC errorpackets. The possible causes are as follows:

(1) Data transmission is interfered and error codes occur.(2) The optical power is unstable.(3) The transmit interface on the peer device fails.(4) An error occurs during packet resolution on the local device.

2. Through the preceding log messages, you can find that the two interfaces do not turn Upor Down at the same time.If auto-negotiation is configured, the interconnected interfaces automatically sendnegotiation frames afer receiving optical signals. If both interfaces receive negotiationframes, they both go Up. In this troubleshooting case, the two interfaces do not turn Up orDown at the same time, which indicates that one interface receives negotiation frameswhereas the other does not receive any. Therefore, it can be inferred that a fault occursduring packet transmission over the link.Through the preceding analysis, it can be determined that a fault occurs on the transmissionlink. In this case, the following describes how to locate the fault on the transmission link:

3. Through on-site measurement, it is found that both the receive optical power of the twointerfaces is -20db, which meets the optical modules' requirement. Therefore, the possibilityof a module or optical fiber fault is ruled out.

4. Check the optical fibers and optical modules for other anomalies. You can find that thefiber end is contaminated.

It can be identified that error codes occur on the receive interface due to contamination of thefiber end.



30

Procedure

Step 1 After the fiber end is cleaned, the receive interface goes Up.The fault is thus rectified.

----End

SummaryIn the case of long-distance transmission, ensure that the optical fiber is bent at less than 90degrees, free from damage or contamination, and properly connected.

3.1.3 Severe Packet Loss Occurs After the FE Optical Module IsMistakenly Inserted into a GE Optical Interface

Fault SymptomUsers connected to GE 1/0/0 on the board of the NE80E/40E report that the Internet is slow andsevere packet loss occurs.

Fault Analysis1. Check logs on the NE80E/40E. No exception is displayed.2. Run the display interface gigabitethernet1/0/0 command to check the interface status. It

is found that the interface and protocol are both Up and no CRC error occurs.The maximum bandwidth of the interface is 1 Gbit/s whereas the maximum bandwidth ofthe optical module is 155 Mbit/s. It can be inferred that the optical module mismatches theinterface, which causes severe packet loss.

Procedure

Step 1 Replace the FE optical module with a GE optical module and insert the GE optical module intothe interface. Then, users can access the Internet normally and the fault is rectified.

----End

SummaryThe mismatch between the optical module and the interface causes severe packet loss. Theappearances of the FE optical module and the GE optical interface module are the same. Thus,check the parameters of the optical module carefully before inserting the optical module intothe interface.

3.1.4 A Device Cannot Go Up Because the 10GE WAN Board DoesNot Match the Multi-mode Optical Module

Fault SymptomRouter A and Router B are connected through two 10GE WAN interfaces that are installed withtwo multi-mode optical modules. Indicators on both interfaces are off, indicating that the statusof the two interfaces is Down.



31

Figure 3-1 Networking diagram for the problem that a device cannot go Up because the 10GEWAN board does not match the multi-mode optical module

Router A Router B

GE1/0/1 GE1/0/2

Fault Analysis1. Run the display interface gigabitethernet 1/0/1 command to check the interface status.

The command output shows that both the input optical power (Rx Power) and output opticalpower (Tx Power) of the interface are in the normal range.

2. Replace the current multi-mode optical module and optical fiber with another multi-modeoptical module and optical fiber. The interface still cannot go Up.

3. Replace the current multi-mode optical module and optical fiber with a single-mode opticalmodule and optical fiber and the interface goes Up. Then, replace the single-mode opticalmodule and optical fiber with the multi-mode optical module and optical fiber, the faultoccurs again.

Because another two devices using 10GE WAN boards installed with multi-mode opticalmodules can communicate on the current network, the possibility that 10GE WAN boards donot support multi-mode optical modules is excluded. It is confirmed that the multi-mode opticalmodules used on the current network may be from different manufacturers. Only optical modulesof certain manufacturers are applicable to both 10GE WAN boards and 10GE LAN boards, andoptical modules of other manufacturers are applicable to only 10GE LAN boards. For security,use multi-mode optical modules on 10GE LAN boards rather than WAN boards or POS boards.

Procedure

Step 1 Replace 10GE WAN boards on the two devices with 10GE LAN boards.

----End

SummaryUsing 10GE LAN boards rather than 10GE WAN boards on the devices connected throughmulti-mode optical fibers is recommended. 10GE WAN boards are usually used for connectingtransmission devices.



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4 ATM Interface Troubleshooting

About This Chapter

4.1 Two ATM Interfaces Fail to Ping Each Other

HUAWEI NetEngine80E/40E RouterTroubleshooting - Physical Connection and Interfaces 4 ATM Interface Troubleshooting


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4.1 Two ATM Interfaces Fail to Ping Each Other

4.1.1 Common Causes

This fault is commonly caused by one of the following:

l Optical fibers do not match optical modules on ATM interfaces.l Optical fibers of ATM interfaces are damaged.l The configurations on the interconnecting ATM interfaces are inconsistent. The frame

format, clock mode, or scrambling function on one interface is different from that on theother interface.

4.1.2 Troubleshooting Flowchart

After two NE80E/40Es are connected to each other using ATM interfaces and configured withthe ATM service, the two ATM interfaces fail to ping each other.

Figure 4-1 shows the troubleshooting flowchart.



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Figure 4-1 Troubleshooting flowchart for the ping failure between interconnecting ATMinterfaces

The ATM interfaces cannot communicate with

each other

The State of the

physical layer is up

Check fibers and other hardware

The problem is solved?

The configurations on

both ends are consistent?

No

Reconfigure both ends and enable the m to be consistent


No

No

No

Yes

The OAM is initiated?

Initiate OAM and set the frequencies on

both ends to be consistent


No

No

YesEnd

Yes

Yes

The ARP entries are generated?


No

No

Yes

Yes

The state of PVC is up?


No

Yes

Reconfigure both ends and enable the m to be consistent


No Check the count on both ends

Yes

Yes

Yes

Yes

Seek technology support

End

No

ARP troubleshooting

4.1.3 Troubleshooting Procedure



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ContextNOTESaving the results of each troubleshooting step is recommended. If your troubleshooting fails to correctthe fault, you will have a record of your actions to provide Huawei technical support personnel.

Procedure

Step 1 Check that the physical status of ATM interfaces is Up.

Run the display interface atm command to view physical status of the local ATM interface.

l If the current state field displays Administratively down, run the undo shutdowncommand in the interface view to start the interface.

l If the current state field displays down, perform the following operations:– Check whether the ATM interface is connected to the peer end using optical fibers,

whether the optical fibers in the sending and receiving directions are properly connectedand securely inserted, and whether the related status indicator is on.

– Check whether alarm information is displayed under the SDH alarm or SONET errorfield.

If the preceding check items of the local ATM interface are normal, repeat the precedingoperations to check whether the physical status of the ATM interface on the peer end is Up.

If the fault persists, go to the next step.

Step 2 Check that configurations on the two ATM interfaces are consistent.

1. Run the display interface atm command to check whether the following configurationson the two interfaces are consistent:l If the Scramble fields on the two ends display different information, run the

scramble or undo scramble command to enable or disable the scrambling function onthe two interfaces.

l If the MTU fields on the two ends display different information, run the MTU commandon the two interfaces to configure a same MTU on the two ends.

l If the values of the clock fields on the two interfaces do not match each other, takemeasures to ensure that:– If a device serves as data connection equipment (DCE), the ATM interface on the

device is configured to work in master clock mode.– If a device serves as data terminal equipment (DTE), the ATM interface on the device

is configured to work in slave clock mode.– If the two ATM interfaces are directly connected using optical fibers, or connected

based on Wavelength Division Multiplexing (WDM), one ATM interface isconfigured to work in master clock mode, and the other one is configured to workin slave clock mode.

– If the two ATM interfaces are connected using a SONET or an SDH device, the twoATM interfaces are configured to work in slave clock mode.

By default, an ATM interface works in master clock mode.2. Run the display this command to check whether

the frame-format sonet field is configured on the two ATM interfaces. If configurationinconsistency exists, run the frame-format command to configure the same encapsulationmode on both ATM interface.



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3. Run the display atm pvc-info command to check whether the ENCAP fields show thatthe two ends use the AAL5 encapsulation mode for PVC. If the two ends use differentencapsulation modes, run the encapsulation command on the ATM interface views toconfigure a same encapsulation mode.


Step 3 Check that the local end has the ARP entry corresponding to the peer end.

Run the display arp slot command to check whether the two ends learn ARP entries correctly.If one end does not learn the ARP entry corresponding to the other end, locate the fault basedon "Troubleshooting-IP Forwarding and Routing".


Step 4 Check that permanent virtual channel (PVC) status on the two ends is Up.

Run the display atm pvc-info command to check whether the PVC STATE field displaysUp.

If the VPI or VCI values of the PVC on the two ends are different, run the pvc command in theATM interface views to configure a same VPI or VCI value.


Step 5 Check that OAM is enabled and OAM configurations are correct on the two ends.

Run the display this command on the ATM interface views to check whether OAM is enabled,and whether OAM cell sending frequencies are consistent on the two ends.

If the peer end is enabled with the OAM F5 Loopback function, but the local end is not configuredwith OAM or does not support response to OAM Loopback cells, the PVC will go Down. If theOAM cell sending frequencies are inconsistent on the two ends, there is a possibility that thePVC goes Down. (After being enabled with the OAM F5 Loopback function, the peer end willcontinuously send OAM Loopback cells to the local end, and request for Replay packets fromthe local end. If the peer end receives no response from the local end within a specific period,it will send OAM RDI alarm cells. At the same time, the PVC will go Down.)


Step 6 Collect the following information and contact Huawei technical support personnel.l Results of the preceding troubleshooting procedurel Configuration files, log files, and alarm files of the devices

----End

4.1.4 Relevant Alarms and Logs

None.



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Documents

Troubleshooting - Physical Connection and Interfaces(V600R003C00_02)