Frame Relay - Address Mapping

Address Mapping in Frame Relay Circuits

A router needs a method to map a DLCI to an IP address, similar to the way ARP maps a MAC address to an IP address.  This is accomplished in two ways:

1. Inverse ARP - 
• Default config for Frame Relay
• provider uses LMI to send a list of DLCIs to the local router, and the local router sends Inverse ARP requests to all other DLCIs, asking for their IP address.  All DLCIs respond with IP address.  
• If you have multiple DLCIs, your interface becomes a multipoint interface, however - Inverse ARP does not work with subinterfaces
2. Static Mapping
• Complete control, but more config
• Assign IP addresses to DLCIs
• R1(config-if)#frame-relay map ip 192.168.5.2 503 broadcast