Frame Relay Configuration

Nerd Cafe

Step 1: Setting Up the GNS3 Topology

1. Open GNS3 and create a new project.

2. Drag and drop three routers (R1, R2, R3) onto the workspace.

3. Add a Frame Relay Switch (FRSW1) from the GNS3 devices.

4. Connect the routers to the Frame Relay switch:

   • R1 to FRSW1

   • R2 to FRSW1

   • R3 to FRSW1

5. Use Serial Connections for the links.

Frame relay Topology

Step 2: Configuring the Frame Relay Switch (FRSW1)

• Right-click on the Frame Relay Switch (FRSW1) and open its configuration.

• Configure the DLCIs (Data-Link Connection Identifiers):

[Add DLCI mappings]

Interface 1 --> Interface 2, DLCI 102
Interface 1 --> Interface 3, DLCI 103
Interface 2 --> Interface 1, DLCI 201
Interface 2 --> Interface 3, DLCI 203
Interface 3 --> Interface 1, DLCI 301
Interface 3 --> Interface 2, DLCI 302

Step 3: Configuring Router R1

• Access R1 CLI and enter global configuration mode:

R1#configure terminal
R1(config)#interface serial 3/0
R1(config-if)#encapsulation frame-relay
R1(config-if)#no shutdown
R1(config)#interface serial 3/0.102 point-to-point
R1(config-subif)#ip address 192.168.102.1 255.255.255.252
R1(config-subif)#frame-relay interface-dlci 102
R1(config-fr-dlci)#exit
R1(config-subif)#exit
R1(config)#interface serial 3/0.103 point-to-point
R1(config-subif)#ip address 192.168.103.1 255.255.255.252
R1(config-subif)#frame-relay interface-dlci 103
R1(config-fr-dlci)#

Step 4: Configuring Router R2

• Access R2 CLI and enter global configuration mode:

R2#configure terminal
R2(config)#interface serial 3/0
R2(config-if)#encapsulation frame-relay
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface serial 3/0.201 point-to-point
R2(config-subif)#ip address 192.168.102.2 255.255.255.252
R2(config-subif)#frame-relay interface-dlci 201
R2(config-fr-dlci)#exit
R2(config-subif)#exit
R2(config)#interface serial 3/0.203 point-to-point
R2(config-subif)#ip address 192.168.203.1 255.255.255.252
R2(config-subif)#frame-relay interface-dlci 203

Step 5: Configuring Router R3

• Access R3 CLI and enter global configuration mode:

R3#configure terminal
R3(config)#interface serial 3/0
R3(config-if)#encapsulation frame-relay
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface serial 3/0.301 point-to-point
R3(config-subif)#ip add 192.168.103.2 255.255.255.252
R3(config-subif)#frame-relay interface-dlci 301
R3(config-fr-dlci)#exit
R3(config-subif)#exit
R3(config)#interface serial 3/0.302 point-to-point
R3(config-subif)#ip address 192.168.203.2 255.255.255.252
R3(config-subif)#frame-relay interface-dlci 302

Step 6: Verifying Frame Relay Configuration

• Check DLCI mappings on each router:

R1#show frame-relay map
Serial3/0.102 (up): point-to-point dlci, dlci 102(0x66,0x1860), broadcast
          status defined, active
Serial3/0.103 (up): point-to-point dlci, dlci 103(0x67,0x1870), broadcast
          status defined, active
R1#

• Check Frame Relay LMI (Local Management Interface) status:

R1#show frame-relay lmi

LMI Statistics for interface Serial3/0 (Frame Relay DTE) LMI TYPE = ANSI
  Invalid Unnumbered info 0             Invalid Prot Disc 0
  Invalid dummy Call Ref 0              Invalid Msg Type 0
  Invalid Status Message 0              Invalid Lock Shift 0
  Invalid Information ID 0              Invalid Report IE Len 0
  Invalid Report Request 0              Invalid Keep IE Len 0
  Num Status Enq. Sent 278              Num Status msgs Rcvd 279
  Num Update Status Rcvd 0              Num Status Timeouts 0
  Last Full Status Req 00:00:34         Last Full Status Rcvd 00:00:34
R1#

• Verify connectivity using ping:

From R1, ping 192.168.102.2 (R2) and 192.168.103.2 (R3):

R1#ping 192.168.102.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.102.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/11/20 ms
R1#ping 192.168.103.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.103.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/16/24 ms
R1#

From R2, ping 192.168.203.1 (R1).

R2#ping 192.168.203.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.203.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/44/88 ms
R2#

Keywords

Frame Relay, GNS3, router configuration, DLCI, Frame Relay switch, serial interface, encapsulation, IP address, Frame Relay map, Frame Relay LMI, routing protocols, RIP, OSPF, static mapping, dynamic mapping, network topology, simulation, networking, IP routing, data link, connectivity, سیسکو