Learning by Doing: CISCO Certified Network ... - SCN Research

Frame Relay Operation and Troubleshooting
Objective:
To learn how to troubleshooting frame relay problems.
Theory of operation:
Frame relay is a layer 2 technology. Troubleshooting it is simple. It is when frame is
combined with other stuff that it becomes complicated. In a simple, basic frame relay
connection you only need to configure:
1. the ip addresses on the same subnet with the proper mask
2. set the encapsulation type to frame relay
3. bring the interface up
4. set the lmi-type, if needed.
That is it. To troubleshoot we can use our OSI layer-by-layer technique:
Snapshot of activity: show frame-relay pvc
show controller s0/0 layer 1
show interface s0/0 layer 1
show frame-relay pvc layer 2
show frame-relay lmi layer 2
debug frame-relay events layer 2
show frame-relay map layer 2/3
show ip route layer 3
Step-By-Step Instructions:
1. Frame relay is one of the easier problems to troubleshoot because there really
is not much that can go wrong with frame relay: it either works or it doesn’t.
Let’s start by viewing our available frame relay show and debug commands. I
have high-lighted some of the more commonly-used commands:
router#sh frame ?
end-to-end
fragment
ip
lapf
lmi
map
pvc
qos-autosense
route
svc
Frame-relay end-to-end VC information
show frame relay fragmentation information
show frame relay IP statistics
show frame relay lapf status/statistics
show frame relay lmi statistics
Frame-Relay map table
show frame relay pvc statistics
show frame relay qos-autosense information
show frame relay route
show frame relay SVC stuff
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