Figure 5-11
Troubleshooting flowchart for an LCP negotiation failure
PPP configurations
on the two ends of the link
are correct?
Physical status of the
interface is Up?
Interface can
sent and receive protocol
packets?
Link is loop-free?
Modify PPP
configurations
Locate and rectify
transmission or
lower-layer faults
Eliminate the
loop
Locate and rectify
transmission or
lower-layer faults
LCP negotiation fails
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
Link delay is tolerant
Check the link
delay
Is fault rectified?
Yes
No
Yes
No
Yes
No
Yes
No
Troubleshooting Procedure
NOTE
Saving the results of each troubleshooting step is recommended. If your troubleshooting fails to correct
the fault, you will have a record of your actions to provide Huawei technical support personnel.
Procedure
Step 1
Check that PPP configurations on the two ends of the link are correct.
Run the
display this
command in the view of the interface whose protocol status is Down to
check PPP configurations.
[Huawei-Serial2/0/0]
display this
#
interface Serial2/0/0
link-protocol ppp
undo shutdown
ip address 10.10.1.1 255.255.255.0
#
return
Huawei AR2200-S Series Enterprise Routers
Troubleshooting
5 WAN
Issue 01 (2012-01-06)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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