• show frame-relay pvc is useful for viewing the status of statically or dynamically defined PVCs. The
output for each PVC is detailed. The output also gives information on each circuit that specifies the
receipt or transmission of FECN/BECN packets. FECN and BECN deal with congestion in the Frame
Relay network, so obviously, a low number is preferable. The output also details the number of discard
eligible (DE) packets received for which a low number is better.
• show frame-relay lmi allows you to check the status of individual PVCs and to monitor the
communication status between the router and the switch. This command show shows the number of LMI
messages sent and received across the link between the router and the switch. The LMI type can be
specified differently for each interface, so the type is specified in the output. This command also shows
the LMI input/output information.
• debug frame-relay lmi is probably the most useful tool in verifying and troubleshooting Frame Relay
problems. This command makes it possible to watch the real-time communication between the router and
the switch. Each request sent from the router to the switch is noted, and the counter is incremented by 1
with each request. LMIs sent from the switch to the router by the service provider are noted and also are
incremented by 1 with each request. As long as both numbers are greater than 0, the router should be
functioning normally at Layers 1 and 3.
• show frame-relay map is used to view the DLCI mappings that have been created. They can be static
or dynamic and are noted as such in the command output.