How to configure Frame Relay on Cisco a Router
The figure below shows the basic Frame Relay configuration on a Cisco router, connected directly to a dedicated Frame Relay switch, or DCE.
All router interface had been configured with IP addresses and routing protocol - RIPv2.
R1
R1#config t
R1(config)#interface serial 0/0/0
R1(config-if)#encapsulation frame-relay
R1(config-if)#frame-relay lmi-type ansi
R1(config-if)#frame-relay map ip 10.1.2.2 102 broadcast
R1(config-if)#no shutdown
R2
R2#config t
R2(config)#interface serial 0/0/1
R2(config-if)#encapsulation frame-relay
R2(config-if)#frame-relay lmi-type ansi
R2(config-if)#frame-relay map ip 10.1.2.1 201 broadcast
R(config-if)#no shutdown
In the topology above, the frame from R1 use DLCI value 102. It leaves the router (R1) using VC 102. This process of VC-port mapping continues through the WAN until the frame reaches its destination at (R2 with value) DLCI 201, From R2, the frame use DLCI value 201 to identify its network VC to R1.The DLCI is stored in the address field of every frame transmitted.
The LMI( Local Management Identifier) acts like a keepalive mechanism that provides status information about Frame Relay connections between the router (DTE) and the Frame Relay switch (DCE).
The Broadcast Keyword is used because Frame Relay, ATM, and X.25 are non-broadcast multiple access (NBMA) networks, Because NBMA does not support broadcast traffic, using the broadcast keyword is a way to forward routing updates by RIP, EIGRP and OSPF.
Explanation of Terms:
