Datasheet

Lab – Configuring Frame Relay and Subinterfaces
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Part 2: Configure a Frame Relay Switch
In Part 2, you will configure a Frame Relay switch. You will create permanent virtual circuits (PVCs) and
assign Data Link Connection Identifiers (DLCIs). This configuration creates two PVCs: one from R1 to R3
(DLCI 103), and one from R3 to R1 (DLCI 301).
Step 1: Configure the FR router as a Frame Relay switch.
The frame-relay switching command enables Frame Relay switching globally on a router, allowing it to
forward frames based on the incoming DLCI rather than an IP address.
FR(config)# frame-relay switching
Step 2: Change the interface encapsulation on S0/0/0.
Change the interface encapsulation type to Frame Relay. Like HDLC or PPP, Frame Relay is a data-link layer
protocol that specifies the framing of Layer 2 traffic.
FR(config)# interface s0/0/0
FR(config-if)# encapsulation frame-relay
Step 3: Change the interface type to DCE.
Changing the interface type to DCE tells the router to send Local Management Interface (LMI) keepalives and
allows Frame Relay route statements to be applied.
Note: Frame Relay interface types do not need to match the underlying physical interface type. A physical
DTE serial interface can act as a Frame Relay DCE interface, and a physical DCE interface can act as a
logical Frame Relay DTE interface.
FR(config)# interface s0/0/0
FR(config-if)# frame-relay intf-type dce
Step 4: Configure DLCI.
Configure the router to forward incoming traffic on interface S0/0/0 with DLCI 103 to S0/0/1 with an output of
DLCI of 301.
FR(config-if)# frame-relay route 103 interface s0/0/1 301
FR(config-if)# no shutdown
Step 5: Configure Frame Relay on S0/0/1.
FR(config)# interface s0/0/1
FR(config-if)# encapsulation frame-relay
FR(config-if)# frame-relay intf-type dce
FR(config-if)# frame-relay route 301 interface s0/0/0 103
FR(config-if)# no shutdown
Step 6: Verify Frame Relay configuration.
a. Use the show frame-relay pvc command to verify that Frame Relay is configured correctly.
FR# show frame-relay pvc
PVC Statistics for interface Serial0/0/0 (Frame Relay DCE)