Frame Relay

Lab aims

Helping students develop considerable skills of equipment configuration for operation with Frame Relay channel protocol, setting up the network with real FR switches as well as using one of the routers as a Frame Relay switch.

The lab is performed using GNS3 emulator. It is expected that the student is already acquainted with the corresponding theoretical material, which is not explained in this lab. In order to brush up on the theoretical material, one should use textbooks on Cisco ICND1 and ICND2.

Description

1. Build the network which is presented on the image below. Network addresses marked in red must be configured in Loopback 1 interfaces as they are meant for emulation of local networks connected to the routers.

2. Use Frame Relay global addressing: DLCI №101 corresponds to R1 router, 102 corresponds to R2 and so on. The example of FR1 switch configuration is presented below. The switches must be configured in a way so that routers R1, R2, and R3 have complete connectivity. Routers R3 and R5 must also be connected. Router R4 will perform functions of a FR switch (so far it's not necessary to be configured now).

3. Use 7200 series routers. Add the following modules to all routers: C7200-IO-FE and PA-4T+. The latter has four serial ports which will be used for connection to Frame Relay switches. An example of configuration of the router hardware is presented on the image below.

4. Switch on all serial interfaces connected to the network on all routers.

5. Using encapsulation frame-relay command configure encapsulation of Frame Relay on the connected serial interfaces of R1, R2, and R3 routers.

6. Find out about which DLCI number the switches send information to every router.

R1#sho frame-relay pvc

PVC Statistics for interface Serial1/0 (Frame Relay DTE)

Active Inactive Deleted Static
Local 0 0 0 0
Switched 0 0 0 0
Unused 2 0 0 0

DLCI = 102, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial1/0

input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
pvc create time 00:02:08, last time pvc status changed 00:02:08

DLCI = 103, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial1/0

input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 0 in pkts dropped 0
out pkts dropped 0 out bytes dropped 0
in FECN pkts 0 in BECN pkts 0 out FECN pkts 0
out BECN pkts 0 in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
pvc create time 00:02:08, last time pvc status changed 00:02:08
R1#

7. Use addresses from 192.168.0.0/24 network for the network between R1 and R3 routers. For example, use 192.168.0.1 for router R1. Assign the corresponding addresses in Serial1/0 interfaces for R2 and R3 routers.

8. Find out which LMI type is used by entering sho int se 1/0 command.

9. Make sure that Inverse ARP functions correctly using show frame-relay map command.

R1#sho frame-relay map
Serial1/0 (up): ip 192.168.0.2 dlci 102(0x66,0x1860), dynamic,
broadcast,, status defined, active

10. Check whether there is connectivity between R1 and R2 routers using ping command.

R1#ping 192.168.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.0.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/57/72 ms

11. Shutdown Serial 1/0 interfaces on R1 and R2 routers. Switch off the above mentioned protocol using no frame-relay inverse-arp interface command. Switch on the interfaces. Make sure that there are no correct IP-DLCI pairs.

12. Use frame-relay map ip interface command with the corresponding parameters in order to adjust the static map between the IP address of the nearby device and its DLCI.

R1(config-if)#frame-relay map ip 192.168.0.2 102
R1(config-if)#^Z
R1#sho frame-relay map
Serial1/0 (up): ip 192.168.0.2 dlci 102(0x66,0x1860), static,
CISCO, status defined, active

13. Make sure that the static mapping functions properly using ping command.

14. Shutdown the interfaces being adjusted, delete the static maps, switch on support of Inverse ARP protocol, and then switch the interfaces back on. Make sure that the IP-DLCI dynamic mapping took place once more.

15. Create Serial1/0.1 multipoint sub-interface on router R3. Assign the corresponding IP address to it. Use frame-relay interface-dlci command with the necessary parameter in order to add the numbers of virtual channels required for connection to R1 and R2. An example of such configuration is presented below.

interface Serial1/0
no ip address
encapsulation frame-relay
serial restart-delay 0
!
interface Serial1/0.1 multipoint
ip address 192.168.0.3 255.255.255.0
frame-relay interface-dlci 101
frame-relay interface-dlci 102

16. Make sure that there is connectivity between R1, R2, and R3 routers using ping command.

17. Adjust dynamic EIGRP routing (one should switch off dynamic summarization of routes using no auto-summary command) in serial interfaces (sub-interfaces) on R1-R3 routers. Configure the redistribution of data about the connected networks into EIGRP using redistribute connected command.

18. Make sure that the correct routing information appeared in routing tables of R1-R3 routers. Make sure that Loopback 1 interfaces on the nearby routers are available.

19. Create a new point-to-point sub-interface on R3 router. Set DLCI attached to it. It will be used for the data exchange with R5 router. Assign an IP subnet for the connection between R3 and R5. Attach an IP address from the assigned subnet for the new sub-interface.

20. Also, create a point-to-point interface on R5, connect a DLCI to it for connection with R3, and adjust a free address from the subnet that you just assigned.

21. Examine which DLCI are known to R3 and R5 routers. Pay particular attention to their statuses. Try to explain what you are seeing.

22. Switch on both serial interfaces used on R4 router. Enter frame-relay switching command in the global configuration mode and frame-relay intf-type dce command for Serial 1/1 interface (connection to R5). The above-mentioned command switches the interface for DCE mode. The command is not necessary to enter in all other cases as the functions of Frame Relay DCE device are performed by FR switch.

23. Now one needs to configure R4 for frames switching that are transferred through a certain PVC of one interface to a certain PVC of the other interface. One can do this by entering frame-relay route interface command with the corresponding parameters: at first one needs to choose the DLCI number of the current interface and then specify the new interface and new DLCI number. In the listing below one can see an example of commutation of DLCI №107 from Serial 1/0 interface to DLCI №103 of Serial 1/1 interface.

interface Serial1/0
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay route 107 interface Serial1/1 103
!
interface Serial1/1
no ip address
encapsulation frame-relay
serial restart-delay 0
frame-relay intf-type dce
frame-relay route 103 interface Serial1/0 107

24. Find out how the status of DLCI №103 changed on R5 router. Explain the reason for such changes.

25. Make sure that there is connectivity between R3 and R5 routers.

26. Adjust EIGRP dynamic routing protocol for operation in the channel between R3 and R5 routers. Redistribute the information about the connected networks to EIGRP on R5 router. Make sure that the data exchange between Loopback 1 interfaces of R1 and R5 routers is available. Find out the route through which the data are transferred. Explain why the data are transferred in this exact way.

27. Propose certain changes in the current network so that the data between R1 and R5 are transferred directly, or in other words bypassing R3 router.

28. Find out what interface types are available in the output of frame-relay route command. Think up a situation where a Tunnel interface could be used. Build the corresponding network in which the usage of tunnel is necessary. Carry out the simulation in the emulator of the built network.
It's a creative and obligatory task.

29. Think up and implement a more complicate topology of the L2 segment of Frame Relay network. Carry out the data exchange between the routers connected to the network in different ways using an FR cloud.
This one is a creative task which is not obligatory.

Download the PDF file with the description of the lab.

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