242 CHAPTER 16: CONFIGURING LAPB AND X.25
■ Facility options inhibited by network have been carried.
Troubleshooting: if the address is configured incorrectly, change the configuration.
For the last two causes, please consult the network management department for
correct channel range and permissible facility options.
Fault 3: The virtual circuit can be established, but is frequently reset or
cleared during data transmission.
Troubleshooting: It is very likely that the flow control parameters are set
incorrectly. For the back to back direct connection, check the sending window and
receiving window of the local and peer to see whether they match each other. In
case it is connected to public packet networks, consult the network management
department to correct flow control parameters.
Fault 4: The request to set Permanent virtual circuits (PVCs) is rejected.
Troubleshooting: if the channel section of the permanent virtual circuit is disabled,
the X.25 will reject the request to set a permanent virtual circuit. In this case,
simply enable the permanent virtual circuit channel section.
Fault 5: After configuring SVC application of XOT, you cannot ping
through
Troubleshooting: there are various reasons. You may first check if the physical and
protocol statuses of the interface are UP. If the interface status is DOWN, check if
the physical connection and bottom configuration are correct. If the interface is
properly configured, then check the SVC configuration. If SVC is also properly
configured, check the XOT configuration.
Fault 6: After configuring PVC application of XOT, you cannot ping
through
Troubleshooting: there are various reasons. You may first check if the physical and
protocol statuses of the interface are UP. If the interface status is DOWN, check if
the physical connection and configuration are correct. If the interface is properly
configured, then check the PVC configuration. If PVC is also properly configured,
check the XOT configuration.
Fault 7: Annex G DLCI is used for interconnection, the link layer protocol is
up, and DLCI has been in place after negotiation. However, the remote end
cannot be pinged.
Troubleshooting:
■ Check whether the X.25 protocol is up at both ends of the Annex G DLCI by
using the
display fr pvc-info command. Both the Frame Relay interface
and DLCI number should be explicitly specified in the command.
■ Check whether the proper map between the Frame Relay address and the
destination IP address has been configured on the router at each ends.
■ Check whether the proper X.25 template has been configured for the Annex G
DLCI on each ends, and whether the local X.121 address has been correctly
mapped to the X.25 address for the destination IP address on each ends.
■ Check whether X.25 SVC has been correctly set up by executing the display
x25 vc
command.