Nortel Networks 8000 - Manual (Page 367)

Nortel Secure Router 8000 Series
Configuration -WAN Access 8 Frame relay configuration
• When Router A pings 2.2.2.65, according to the map table, it chooses the PVC with
DLCI as 17 to send the packet. When the packet reaches Router B, FR of Router B
cannot find the mapping information with DLCI as 17. Thus, the packet is discarded.
Therefore, Router A cannot ping through 2.2.2.65.
• When Router B pings 2.2.2.67, it chooses the PVC with DLCI as 18 to send the packet.
The mapping information with DLCI as 18 exists on Router A; therefore, Router B can
ping through 2.2.2.65.
The inconsistent information between Router A and Router B causes the ping to fail when the
Router A pings through Router B.
—End
Troubleshooting procedure
Do as follows on Router A:
Step 1 Run the system view command to enter the system view.
Step 2 Run the interface serial1/0/0.1 command to enter the sub-interface view.
Step 3 Run the fr dlci command to configure the FR PVC.
Step 4 Run the quit command to return to the sub-interface view.
Step 5 Run the ip address command to configure the IP address of the sub-interface.
Run the shutdown command and the undo shutdown command or the restart command on
Serial1/0/0 on Router B to enable the PVC negotiation afresh.
—End
After the configuration is complete, the mappings on Router A and Router B are updated. The
routers learn the mapping of the PVC with DLCI as 17. Router A and Router B can
successfully ping each other.
Summary
To configure the FR PVC, note the following points:
• According to the map entry, it is decided through which PVC the packet is sent.
• If you want the packet is sent from a specific PVC, do not configure other PVCs on the
interface.
• DTE devices can learn all the PVCs of DCE devices through the LMI protocol. Using
the
display fr pvc-info command, you can check the related information.
• It is suggested to configure the PVC of DTE side on the sub-interface. Configuring the
PVC of DTE side on the sub-interface can ensure the PVC on the sub-interface can
create the mapping information on the opposite end because only the DTE main interface
can learn the PVC from the DCE side.
• After the IP address is configured on DTE, all the PVCs that includes the learned PVC
will send the InARP protocol packet to DCE and create the mapping information on
DCE. New mapping information that corresponds to the existing address cannot be
created.
In this case, the mapping information on Router B is the PVC (with DLCI as 18) learned by
Router A. The InARP information sent by Router A from the PVC with DLCI as 17 does not
Issue 5.3 (30 March 2009) Nortel Networks Inc. 8-77