This chapter focused on the practical aspects of Frame Relay technology by discussing the Cisco IOS configuration commands required to enable basic Frame Relay operation on a Cisco router. This chapter started by explaining the configuration tasks required to enable Frame Relay on a supported interface, including configuring LMI. LMI is a set of maintenance protocols for Frame Relay. LMI autosense allows a Cisco router to dynamically learn the LMI type supported by the Frame Relay switch. LMI autosense is enabled by default on Cisco IOS Release 11.2 or later.
This chapter also explained the frame-relay lmi-type configuration command, which allows users to specifically select the LMI type to be used. Dynamic Inverse ARP is enabled by default, and it allows a router to perform the remote network layer address to local DLCI resolution dynamically without user intervention. The frame-relay map configuration command was also introduced. It allows the user to perform static address mapping.
The configuration tasks involved in creating a logical subinterface under the physical interface were discussed. Both point-to-point and multipoint subinterface creation were explained. Because a Cisco router can be set up to function as a Frame Relay switch, the configuration examples for configuring a Frame Relay switch to use both local and global significant addressing were demonstrated. The final sections in this chapter introduced and explained the Cisco IOS show and debug commands, which are valuable for monitoring and troubleshooting basic Frame Relay operations.
This chapter concludes Part I of this book. Part II of this book looks at the Cisco IOS features for performing traffic policing and shaping.