31 Days Before Your CCNA Exam

Day 2 3436. Every 60 seconds, routers send Inverse ARP messages on all active DLCIs. Every 10 seconds,the router exchanges LMI information with the switch (keepalives).7. The router changes the status of each DLCI to active, inactive, or deleted, based on the LMIresponse from the Frame Relay switch.Figure 2-8 illustrates Steps 5–7 of this process.Figure 2-8Stages of Inverse ARP and LMI Operation ContinuedDLCI = 100172.168.5.5Frame RelayCloudDLCI = 400172.168.5.7Hello, I am 172.168.5.7.45Frame Relay Map172.168.5.7 DLCI 100 ActiveFrame Relay Map172.168.5.5 DLCI 400 Active56Hello, I am 172.168.5.5.7KeepalivesKeepalives7Configuring and Verifying Frame RelayThe following list summarizes the Frame Relay configuration steps.Step 1Step 2Step 3Step 4Configure the physical interface to use Frame Relay encapsulation (encapsulationframe-relay interface subcommand).Configure an IP address on the interface or subinterface (ip address subcommand).(Optional) Manually set the LMI type on each physical serial interface (frame-relaylmi-type interface subcommand).(Optional) Change from the default encapsulation of cisco to ietf by doing thefollowing:a. For all VCs on the interface, add the ietf keyword to the encapsulationframe-relay interface subcommand.b. For a single VC, add the ietf keyword to the frame-relay interface dlci interfacesubcommand (point-to-point subinterfaces only) or to the frame-relaymap command.Step 5(Optional) If you aren’t using the (default) Inverse ARP to map the DLCI to the nexthoprouter’s IP address, define static mapping using the frame-relay map ip dlci ipaddressbroadcast subinterface subcommand.