Lab 9.2.3: Dial Backup with Dialer Profiles

Objective:

Apply everything you have learned about dial backup and dialer profiles to configure a network in which in the event of a Frame Relay failure the branch office dials both the central site in addition to a separate stub network office when traffic for that site is present.

Scenario:

You have been asked to implement a DDR dial backup link to backup the Frame Relay network between Orlando and Atlanta. You have installed an ISDN line in Orlando to make this possible. Now that Orlando has ISDN, you have come up with the idea to take advantage of that line so that you can connect to the Minneapolis office which also has an ISDN line. Configure a DDR connection between Orlando and Minneapolis. Because Orlando will be using the same line to connect to two different locations, you must use dialer profiles to make this possible.

Lab Tasks:

  1. Cable the lab as shown in the diagram. Use the Adtran Atlas 550 as your ISDN and Frame Relay networks.


    First configure your ISDN BRI lines. Assign the appropriate SPIDs and dialer maps to implement DDR. Use legacy DDR on the Minneapolis and Atlanta routers. Because Orlando will be dialing two different locations, use dialer profiles.

    Atlanta(config)#int bri0/0
    Atlanta(config-if)#ip address 192.168.3.2 255.255.255.0
    Atlanta(config-if)#encapsulation ppp
    Atlanta(config-if)#ppp authentication chap
    Atlanta(config-if)#dialer map ip 192.168.3.1 name Orlando
    5551234
    Atlanta(config-if)#dialer-group 1
    Atlanta(config-if)#isdn switch-type basic-ni
    Atlanta(config-if)#isdn spid1 51055540000001 5554000
    Atlanta(config-if)#isdn spid2 51055540010001 5554001
    Atlanta(config-if)#no shutdown

    Minneapolis(config)#int bri0/0
    Minneapolis(config-if)#ip address 192.168.5.2 255.255.255.0
    Minneapolis(config-if)#encapsulation ppp
    Minneapolis(config-if)#ppp authentication chap
    Minneapolis(config-if)#dialer map ip 192.168.5.1 name Orlando 5551234
    Minneapolis(config-if)#dialer-group 1
    Minneapolis(config-if)#isdn switch-type basic-ni
    Minneapolis(config-if)#isdn spid1 51055570000001 5557000
    Minneapolis(config-if)#isdn spid2 51055570010001 5557001
    Minneapolis(config-if)#no shutdown
    Minneapolis(config)#dialer-list 1 protocol ip permit

    Orlando(config)#int bri0/0
    Orlando(config-if)#dialer pool-member 1
    Orlando(config-if)#isdn switch-type basic-ni
    Orlando(config-if)#isdn spid1 51055512340001 5551234
    Orlando(config-if)#isdn spid2 51055512350001 5551235
    Orlando(config-if)#no shutdown
    Orlando(config)#int dialer 1
    Orlando(config-if)#ip address 192.168.3.1 255.255.255.0
    Orlando(config-if)#encapsulation ppp
    Orlando(config-if)#ppp authentication chap
    Orlando(config-if)#dialer remote-name Atlanta
    Orlando(config-if)#dialer string 5554000
    Orlando(config-if)#dialer pool 1
    Orlando(config-if)#dialer-group 1
    Orlando(config)#int dialer 2
    Orlando(config-if)#ip address 192.168.5.1 255.255.255.0
    Orlando(config-if)#encapsulation ppp
    Orlando(config-if)#ppp authentication chap
    Orlando(config-if)#dialer remote-name Minneapolis
    Orlando(config-if)#dialer string 5557000
    Orlando(config-if)#dialer pool 1
    Orlando(config-if)#dialer-group 2
    Orlando(config)#dialer-list 1 protocol ip permit
    Orlando(config)#dialer-list 2 protocol ip permit

  2. Now configure your Frame Relay and dial backup commands on the Orlando and Atlanta routers.

    Orlando(config)#int s0/0
    Orlando(config-if)#encapsulation frame-relay
    Orlando(config-if)#frame-relay lmi-type ansi
    Orlando(config)#int s0/0.16 point-to-point
    Orlando(config-if)#ip address 192.168.4.1 255.255.255.0
    Orlando(config-if)#frame-relay interface-dlci 16
    Orlando(config-if)#backup interface dialer 1
    Orlando(config-if)#backup delay 30 60

    Atlanta(config)#int s0/0
    Atlanta(config-if)#encapsulation frame-relay
    Atlanta(config-if)#frame-relay lmi-type ansi
    Atlanta(config)#int s0/0.17 point-to-point
    Atlanta(config-if)#ip address 192.168.4.2 255.255.255.0
    Atlanta(config-if)#frame-relay interface-dlci 17

  3. Now configure your static routes on all of the routers that will enable communication between all sites. Use default routes where necessary to push traffic towards the central site.

    Atlanta(config)#ip route 192.168.1.0 255.255.255.0 192.168.4.1
    Atlanta(config)#ip route 192.168.1.0 255.255.255.0 192.168.3.1 200
    Atlanta(config)#ip route 192.168.6.0 255.255.255.0 192.168.4.1
    Atlanta(config)#ip route 192.168.6.0 255.255.255.0 192.168.3.1 200

    Orlando(config)#ip route 0.0.0.0 0.0.0.0 192.168.4.2
    Orlando(config)#ip route 0.0.0.0 0.0.0.0 192.168.3.2 200
    Orlando(config)#ip route 192.168.6.0 255.255.255.0 192.168.5.2

    Minneapolis(config)#ip route 0.0.0.0 0.0.0.0 192.168.5.1

  4. Test connectivity from Orlando to Atlanta via the Frame Relay link. This should be functional.
  5. Test connectivity from Orlando to Minneapolis via the DDR ISDN link by pinging from Orlando to Minneapolis. This should be functional.
  6. Once you have verified the network is functioning properly, allow the DDR link to timeout.
  7. Check the status of the DDR dial backup link on Orlando. What command(s) could you use?



  8. Disconnect the serial link from the Orlando router and then try to ping Atlanta (192.168.2.1). You may have to ping several times. What happens?






  9. While continuing to ping Atlanta, mix in a few pings to Minneapolis (192.168.6.1).

    What happens?

  10. Look at the links (lights) on your BRI interfaces. What do you see?



  11. Reconnect the Frame Relay link to Orlando. Give the link some time to come back up.
  12. From the Atlanta router, are you able to ping Minneapolis (192.168.6.1)? Does it ping right away? Why?

  13. Disconnect the Frame Relay link on Orlando again.
  14. Try to ping Minneapolis (192.168.6.1) from Atlanta again. Are you able to reach it? Why?






  15.  What would correct this problem?