Frame-relay configuration

Frame relay is one of the WAN protocols you need to understand if you plan to become CCNA-certified. It’s also one of the most difficult protocols to understand for most CCNA students.

Frame-Relay was a very popular WAN technology in the past days. It still is today to some extent. However, it is safe to say that it is being replaced by competing technologies like Ethernet WAN, Multi-Protocol Label Switching (MPLS), and Virtual Private Network (VPN).

Frame relay uses a service provider to provide connectivity. Frame relay is cost cost-effective solution for leased lines.

A virtual circuit is a connection in a frame relay is provides virtual circuits.  Multiple logical connections on the same physical connection.

Data link connection identifier (DLCI) identifies the virtual circuits range (16- 1007) given by the service provider. Local DLCI map with a remote IP address.  Manual or auto-mapping (inverse ARP).

 local management interface (LMI) is used to send keepalive messages between the router and frame relay switch for checking the connectivity.

Fame relay network types

• Point to point
• Point to multi-point

Topology 

TASK; configure point-to-point frame relay, make sure router 1 makes ping to router 2.

R1(config)#interface serial 3/0

R1(config-if)#no shutdown

R1(config-if)#ip address 1.1.1.1 255.0.0.0

R1(config-if)#encapsulation frame-relay

R1(config-if)#end

*Dec  1 19:13:09.207: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/0, changed state to down

R1#show run interface s3/0

Building configuration...

Current configuration : 108 bytes

!

interface Serial3/0

 ip address 1.1.1.1 255.0.0.0

 encapsulation frame-relay

 serial restart-delay 0

end

R1#ping 1.1.1.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.2, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

R3(config)#interface serial 3/1

R3(config-if)#no shutdown

R3(config-if)#ip address 1.1.1.2 255.0.0.0

R3(config-if)#encapsulation frame-relay

R3(config-if)#end

*Dec  1 19:14:34.723: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/1, changed state to down

R3#show ip interface br

Interface              IP-Address      OK? Method Status           Protocol

Serial3/1              1.1.1.2         YES manual up                    down

R3#show run interface serial 3/1

Building configuration...

Current configuration : 108 bytes

!

interface Serial3/1

 ip address 1.1.1.2 255.0.0.0

 encapsulation frame-relay

 serial restart-delay 0

end

R3#ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

*Dec  1 19:22:14.723: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/1, changed state to up

R2(config)#hostname FRSW

FRSW(config)#frame-relay switching

FRSW(config)#interface serial 3/0

FRSW(config-if)#no shutdown

FRSW(config-if)#encapsulation frame-relay

*Dec  1 19:18:48.259: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/0, changed state to up

FRSW(config-if)#encapsulation frame-relay

FRSW(config-if)#frame-relay intf-type dce

FRSW(config-if)#frame-relay lmi-type ?

  cisco

  ansi

  q933a

FRSW(config-if)#frame-relay lmi-type cisco

FRSW(config-if)#frame-relay route 100 interface serial 3/1 200

FRSW(config-if)#exit

FRSW(config)#interface serial 3/1

FRSW(config-if)#no shutdown

FRSW(config-if)#encapsulation frame-relay

FRSW(config-if)#frame-relay intf-type dce

FRSW(config-if)#frame-relay lmi-type cisco

FRSW(config-if)#frame-relay route 200 interface serial 3/0 100

FRSW(config-if)#end

FRSW#show frame-relay route

Input Intf      Input Dlci      Output Intf     Output Dlci     Status

Serial3/0       100             Serial3/1       200             active

Serial3/1       200             Serial3/0       100             active

FRSW#show frame-relay lmi

LMI Statistics for interface Serial3/0 (Frame Relay DCE) LMI TYPE = CISCO

  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. Rcvd 27               Num Status msgs Sent 25

  Num Update Status Sent 0              Num St Enq. Timeouts 0

LMI Statistics for interface Serial3/1 (Frame Relay DCE) LMI TYPE = CISCO

  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. Rcvd 11               Num Status msgs Sent 10

  Num Update Status Sent 0              Num St Enq. Timeouts 0

R1#ping 1.1.1.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 48/59/92 ms

R3#ping 1.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 40/47/60 ms