Lab 5.5.10: Snapshot routing

Objectives:

  • Configure snapshot routing between a central router and a branch office router.

Scenario:

The Phoenix and Denver offices want to exchange routing updates without incurring large telecommunication bills. Your solution is to configure snapshot routing between the two routers.

Notes: 

Lab Tasks:

  1. Cable the lab as shown in the diagram.

  2. The first router to be configured will be the Denver branch office router. Log into the branch office router and enter global configuration mode.

  3. Configure the following basic information into the router:

    • Configure the hostname Denver on the router.

    • Configure the router to prevent the lookup of misspelled words.
    • Configure IGRP routing with AS# 100.
    • Configure the enable password to be cisco.
    • Configure the FastEthernet 0/0 interface with the IP address 192.168.3.1/24.
    • Configure the line VTY 0 4 to request a login with the cisco password.

     

  4. Configure the ISDN BRI connection. The commands to do this are:

    Denver(config)#isdn switch-type basic-ni
    Denver(config)#interface bri 0
    Denver(config-if)#ip address 10.1.1.3 255.255.255.0
    Denver(config-if)#isdn spid1 51055540000001 5554000
    Denver(config-if)#isdn spid2 51055540010001 5554001
    Denver(config-if)#dialer-group 1
    Denver(config-if)#encapsulation ppp
    Denver(config-if)#ppp authentication chap
    Denver(config-if)#dialer idle-timeout 120
    Denver(config-if)#dialer map ip 10.1.1.2 name phoenix broadcast 5551234
    Don't forget the no shutdown command!

  5. Specify what types of traffic will generate a call to the remote router. Traffic that generates a call to another router is called "interesting traffic." In this lab, any IP traffic is considered "interesting" and should generate a call. Configure a dialer-list to specify IP traffic as interesting with the following command. You will also need to specify a username and password for CHAP authentication.

    Denver(config)#dialer-list 1 protocol ip permit
    Denver(config)#username Phoenix password cisco
    Denver(config)#ip host phoenix 192.168.2.1
    Denver(config)#ip route 0.0.0.0 0.0.0.0 10.1.1.2

  6. Configure the Phoenix router with the same basic commands as you did in Denver. This information is as follows:
    • Configure the enable password to be cisco.
    • Configure the FastEthernet 0/0 interface with the IP address 192.168.2.1/24.
    • Configure the line VTY 0 4 to request a login with the cisco password.

  7. Configure the Phoenix ISDN connection with the following commands:

    Phoenix(config)#isdn switch-type basic-ni
    Phoenix(config)#interface bri 0
    Phoenix(config-if)#ip address 10.1.1.2 255.255.255.0
    Phoenix(config-if)#isdn spid1 51055512340001 5551234
    Phoenix(config-if)#isdn spid2 51055512350001 5551235
    Phoenix(config-if)dialer-group 1
    Phoenix(config-if)#encapsulation ppp
    Phoenix(config-if)#ppp authentication chap
    Phoenix(config-if)#dialer idle-timeout 120
    Phoenix(config-if)#dialer map ip 10.1.1.3 name Denver broadcast 5554000

    What is the significance of the word broadcast in the last statement above?

  8. Specify what types of traffic will generate a call to the remote router. Traffic that generates a call to another router is called "interesting traffic." In this lab, any IP traffic is considered "interesting" and should generate a call. We must also configure a username and password for authentication. The commands are as follows:

    Phoenix(config)#username denver password cisco
    Phoenix(config)#dialer-list 1 protocol ip permit
    Phoenix(config)#ip host denver 192.168.3.1
    Phoenix(config)#ip route 0.0.0.0 0.0.0.0 10.1.1.3

  9. Verify connectivity between Phoenix and Denver. What IGRP routes are being advertised?



  10. Can you think of any problems with DDR and IGRP routing updates? Why would you not want to leave this configuration as is?



  11. Now it is time to configure snapshot routing. Phoenix will be the server and Denver will be the client. Set the active period for 5 minutes. The command is as follows:

    Phoenix(config)#interface bri 0/0
    Phoenix(config-if)#snapshot server 5

  12. The commands to configure the snapshot client in Denver are as follows:

    Denver(config-if)#dialer map snapshot 1 name phoenix broadcast 5551234
    Denver(config-if)#snapshot client 5 10 suppress-statechange-update dialer

    The dialer map snapshot interface configuration command establishes a map that the router uses to connect to the Phoenix site router for the exchange of routing updates. The snapshot client interface configuration command sets the length of the active period to five minutes (a value that must match the value set in the snapshot server's configuration) and sets the length of the quiet period to 10 minutes. The suppress-statechange-updates keyword prevents the routers from exchanging updates during connections that are established to transfer user data. The dialer keyword allows the client router to dial up the server router in the absence of regular traffic and is required when you use the suppress-statechange-update keyword.

  13. Save the configuration on both routers and then reload each router.

  14. Issue the command show ip route on each router. Document your findings.










  15. Issue the command show snapshot on each router. Document your findings.



  16. Wait a few minutes, will the Denver router dial the Phoenix router at the end of the quiet period?










  17. Document any other observations your group notices about snapshot routing.