Somethings to look out for when troubleshooting WAN implementation issues:
- Mismatched IPs
- debug ppp authentication – Will show if any authentication issues (password mismatch)
- Encapsulation mismatch – ppp and HDLC for example
- show cdp neighbors detail
- show frame-relay lmi
- show frame-relay map
- show frame-relay pvc
- show running-config
- show interface s0
- Frame relay encapsulation mismatch
- debug frame-relay lmi