1.Common Causes
A ping failure may occur in the following scenarios:
l Basic FR is configured.
l A PVC group is configured.
This fault is commonly caused by one of the following:
l In the scenario where basic FR is configured:
a. No IP address is assigned to the interface.
b. The mapping between the PVC and peer IP address is not generated.
c. The mapping between the PVC and peer IP address is generated but no route is generated.
l In the scenario where a PVC group is configured:
a. No priority is configured for PVCs in the PVC group.
b. The default PVC is not specified in the PVC group and some priorities are not configured for PVCs in the PVC group.
If a ping operation is performed between two indirectly connected devices, check whether static routes are configured on the two devices in addition to checking the preceding items.
2.Troubleshooting Flowchart
Figure 1-1 shows the troubleshooting flowchart in the scenario where basic FR is configured.
Figure 1-1 Troubleshooting flowchart for a ping failure when the link protocol status of two FR Interfaces Is Up
Figure 1-2 shows the troubleshooting flowchart in the scenario where a PVC group is configured.
Figure 1-2 Troubleshooting flowchart for a ping failure when the link protocol status Is Up
3.Troubleshooting Procedure
Saving the results of each troubleshooting step is recommended. If troubleshooting fails to correct the fault, you will have a record of your actions to provide Huawei technical support personnel.
Procedure
l In the scenario where basic FR is configured:
a. Check that a PVC is configured on the DTE-side interface.
Run the display fr pvc-info interface serial command in the system view to check whether there is PVC information.
[Huawei]display fr pvc-info interface Serial
2/0/0:2
PVC statistics for interface Serial2/0/0:2 (DTE, physical
UP)
DLCI = 300, USAGE = UNUSED (00000000),
Serial2/0/0:2
create time = 2008/01/03 19:05:54, status = ACTIVE
InARP = Enable, PVC-GROUP =
NONE
in packets = 0, in bytes =
0
out packets = 0, out bytes = 0
n If no PVC information is displayed, no PVC exists on the interface. Configure the PVC on the DCE-side interface. If you are sure that the PVC exists on the DCE-side interface, you can also configure PVC on the DTE-side interface.
n If the value of the status field is INACTIVE, there is a possibility that no PVC exists on the DCE-side interface. Configure the PVC on the DCE-side interface.
n If the value of the status field is ACTIVE, the PVC functions properly. Go to step 2.
If a sub-interface is configured on the DTE-side interface, configure a DLCI for the sub-interface.
b. Check that the number of PVCs configured on the DTE-side interface does not exceed the threshold.
Run the display fr pvc-info command on the DTE-side interface to check the configured PVCs.
[Huawei]display fr pvc-info
PVC statistics for interface Serial2/0/0:2 (DTE, physical
UP)
DLCI = 300, USAGE = UNUSED (00000000),
Serial2/0/0:2
create time = 2008/01/03 19:05:54, status =
ACTIVE
InARP = Enable, PVC-GROUP =
NONE
in packets = 0, in bytes =
0
out packets = 0, out bytes =
0
If the number of configured PVCs has reached the threshold, no more PVCs can be created.
n If the number of configured PVCs has exceeded the threshold, delete unnecessary PVCs.
n If the number of configured PVCs does not exceed the threshold, go to step 3.
You must delete the DLCI on the DCE and DTE.
c. Check that IP addresses have been assigned to interfaces on both ends.
Run the display this command in the FR interface view to check whether an IP address is assigned to the interface.
[Huawei-Serial2/0/0:2]display
this
#
interface
Serial2/0/0:2
link-protocol
fr
ip address 7.7.7.2
255.255.255.0
#
return
n If no IP address is assigned to the interface, assign an IP address to this interface.
n If an IP address has been assigned to the interface, go to step 4.
d. Check that InARP is enabled on the interface.
Run the display this command on the interface to check the interface configuration.
[Huawei-Serial2/0/0:2]display
this
#
interface
Serial2/0/0:2
link-protocol
fr
undo fr
inarp
ip address 7.7.7.2
255.255.255.0
#
return
n If the undo fr inarp command has been run on the interface, InARP has been disabled on the interface. Run the fr inarp on the interface to enable InARP.
n If InARP has been enabled on the interface, go to step 5.
e. Check that the mapping between the PVC and peer address has been generated.
Run the display fr map-info command to check whether the mapping between the PVC and peer address is generated.
[Huawei-Serial2/0/0:2]display fr
map-info
Map Statistics for interface MFR0/0/0
(DCE)
DLCI = 100, bridge 1,
MFR0/0/0
create time = 2008/01/03 18:25:22, status =
ACTIVE
encapsulation = ietf, vlink = 0,
broadcast
Map Statistics for interface Serial2/0/0:2
(DTE)
DLCI = 300, IP INARP 7.7.7.1,
Serial2/0/0:2
create time = 2008/01/04 15:19:45, status =
ACTIVE
encapsulation = ietf, vlink = 9,
broadcast
n If no mapping is generated, configure the mapping between the PVC and peer address.
n If the mapping has been generated, go to step 6.
f. Check that both ends have reachable routes to each other.
Run the display fib command to check the routing table.
[Huawei-Serial2/0/0:0]display this
#
interface
Serial2/0/0:0
link-protocol
fr
fr interface-type
dce
fr dlci 22
ip address 7.7.7.2
255.255.255.0
#
return
[Huawei-Serial2/0/0:0]display
fib
Route Flags: G - Gateway Route, H - Host Route, U - Up
Route
S -
Static Route, D - Dynamic Route, B - Black Hole
Route
------------------------------------------------------------------------------
FIB
Table:
Total number of Routes :
17
Destination/Mask
Nexthop Flag
TimeStamp Interface
TunnelID
7.7.7.1/32
7.7.7.1 HU
t[2917] S2/0/0:0
0x0
7.7.7.255/32
127.0.0.1 HU
t[2907]
InLoop0
0x0
7.7.7.2/32
127.0.0.1 HU
t[2907]
InLoop0
0x0
50.1.1.255/32
127.0.0.1 HU
t[2519] InLoop0
0x0
50.1.1.1/32
127.0.0.1 HU
t[2519]
InLoop0
0x0
192.168.0.255/32 127.0.0.1
HU t[495]
InLoop0
0x0
192.168.0.23/32 127.0.0.1
HU t[495]
InLoop0 0x0
36.1.1.255/32
127.0.0.1 HU
t[492]
InLoop0
0x0
36.1.1.2/32
127.0.0.1 HU
t[492]
InLoop0
0x0
255.255.255.255/32 127.0.0.1
HU t[484]
InLoop0
0x0
127.255.255.255/32 127.0.0.1
HU t[484]
InLoop0
0x0
127.0.0.1/32
127.0.0.1 HU
t[484]
InLoop0
0x0
127.0.0.0/8
127.0.0.1 U
t[484]
InLoop0 0x0
36.1.1.0/24
36.1.1.2 U
t[492]
VT3 0x0
192.168.0.0/24 192.168.0.23
U t[495]
GE0/0/0
0x0
50.1.1.0/24
50.1.1.1 U
t[2519]
S2/0/1:15 0x0
7.7.7.0/24 7.7.7.2
U t[2907]
S2/0/0:0
0x0
In the command output, the local IP address is 7.7.7.2, the peer IP address is 7.7.7.1, and the information in bold indicates the correct routing entry.
n If the preceding routing entry is not displayed, configure this route.
n If the preceding routing entry is displayed, go to step 7.
g. Collect the following information and contact technical support personnel.
n Results of the preceding troubleshooting procedure
n Configuration files, log files, and alarm files of the device
l In the scenario where a PVC group is configured:
a. Check that the PVC group status of FR interfaces on both ends is Active.
Run the display fr pvc-group command to check the PVC group status.
[Huawei-Serial2/0/0:0]display fr pvc-group
PVC-GROUP-name State
TosType INARP
Interface Type PhyStatus
1 Active
PRECEDENCE Enable Serial2/0/0:0 DTE
Up
n If the PVC group status is not displayed as Active, check the physical status of the interfaces.
n If the PVC group status has been displayed as Active, go to step 2.
b. Check that all the priorities in a PVC group are configured for PVCs in the PVC group.
Run the display this command in the interface view to check the interface configuration.
[Huawei-Serial2/0/0:0]display this
interface
Serial2/0/0:0
link-protocol
fr
fr pvc-group 1
fr dlci
22
fr dlci
33
fr ip precedence 22 0 4
fr ip precedence 33
default
ip address 7.7.7.2
255.255.255.0
#
return
Two types of priorities are available for IP packets: IP precedence and DSCP. The IP preference value ranges from 0 to 7, and the DSCP value ranges from 0 to 63. If no default PVC is specified, all the priorities need to be configured for PVCs in a PVC group. Only one type of priority (either the IP precedence or DSCP) can be configured for PVCs in a PVC group.
n If some priorities in the PVC group are not configured for PVCs in the PVC group, reconfigure priorities for PVCs.
n If all the priorities have been configured for PVCs in the PVC group, go to step 3.
c. Collect the following information and contact technical support personnel.
n Results of the preceding troubleshooting procedure
n Configuration files, log files, and alarm files of the device
----End
