User manual
Nortel Secure Router 8000 Series
Configuration -WAN Access 7 LAPB and X.25 configuration
Issue 5.3 (
30 March 2009) Nortel Networks Inc. 7-75
x25 x121-address 1002
x25 map ip 16.16.16.1 compressedtcp 16.16.16.1 x121-address 1001
ip address 16.16.16.2 255.255.0.0
#
return
7.9 Troubleshooting
This section provides troubleshooting methods for the following faults:
z
LAPB is always disconnected
z
LAPB protocol is up, VC cannot be established
z
X.25 Protocol cannot enter the up status
z
X.25 Protocol is up, VC cannot be established
z
Frequently reset or cleared during data transmission
z
Request to set PVCs is rejected
z
After SVC application of XOT is configured, the ping fails
z
After PVC application of XOT is configured, the ping fails
7.9.1 LAPB is always disconnected
Fault description
Two connected sides are encapsulated with LAPB (or X.25); however, the protocol is always
disconnected.
Fault analysis
The possible cause is that the two ends are working in different modes.
Troubleshooting procedure
Do as follows on the routers:
Step 1 Enable the debugging. You can find that one end sends the SABM frame, and the other sends
the FRMR frame cyclically.
Step 2 Change the operation mode on one side to ensure the operation modes are consistent on both
ends.
----End
7.9.2 LAPB protocol is up, VC cannot be established
Fault description
The LAPB protocol is in the up state; however, the peers cannot ping through each other.