Lab 10.2.3: Weighted Fair Queuing

Objective:

  • To prioritize traffic between the WestCoast router and the EastCoast router using weighted fair queuing.

Scenario:

Our company has given us the task of connecting our east coast office with the west coast office via ISDN. There will be some large file transfers over this link but we do not want them to dominate the link. Since we want low bandwidth applications such as telnet to be able to get through at any time, we have decide to use weighted fair queuing to solve this problem. It is our responsibility to connect these two routers together and configure weighted fair queuing correctly.

Lab Tasks:

  1. Cable the lab as shown in the diagram.
  2. The first router to be configured is the WestCoast router. Log into the router and enter global configuration mode.
  3. Configure the following basic information into the WestCoast router:

    • Configure the hostname WestCoast on the router.
    • Configure the router to prevent the lookup of misspelled words.
    • Configure IGRP routing with the AS# 777. Ensure that no routing updates will be sent out of interface BRI 0.
    • Configure the enable password to be cisco.
    • Configure the Ethernet 0 interface with the IP address 10.100.100.1/24.

  4. The next step is to configure the ISDN BRI connection on the WestCoast router from the global configuration:

    • Configure the ISDN switch type to be National ISDN-1.

    What is the command to set the switch type to National ISDN-1?


    • Configure the username and password of the router to be dialed, the username should be EastCoast, and the password should be cisco.
    • Configure the dialer list to permit IP traffic.
    • Since the routers are not sharing routing tables, we need to configure a static route to the EastCoast routers network. The IP address of the EastCoast network is 10.30.30.0/24 and the IP address to the router is 10.200.200.2/24.
  5. We are going to be using dialer profiles in this lab, so the final part of the basic configuration of the WestCoast router is to configure the BRI interface and dialer interface.
    • Configure the dialer interface with the IP address 10.200.200.1/24.
    • Configure the Service Profile Identifiers: SPID1=51055512340001, SPID2=51055512350001
    • Configure the encapsulation type to be PPP.
    • For security reasons, configure the authentication to be CHAP
    • Apply the dialer list to the interface.

    What is the command to set the authentication type to CHAP?


    • To keep the line from staying connected all of the time, configure the idle timeout to be 60 seconds.
    • Lastly, the router needs to know where to dial. Configure the dialer map with the IP address of the EastCoast router(10.200.200.2), the name of the router to be dialed(EastCoast), and the number to dial(5558000).
  6. Next, Configure the following basic information into the EastCoast router:
    • Configure the hostname EastCoast on the router.
    • Configure the router to prevent the lookup of misspelled words.
    • Configure IGRP routing with the AS# 777. Ensure that no routing updates will be sent out of interface BRI 0.
    • Configure the enable password to be cisco.
    • Configure the Ethernet 0 interface with the IP address 10.30.30.1/24.
  7. The next step is to configure the ISDN BRI connection on the EastCoast router from the global configuration:
    • Configure the ISDN switch type to be National ISDN-1.
    • Configure the username and password of the router to be dialed, the username should be WestCoast, and the password should be cisco.
    • Configure the dialer list to permit IP traffic.
    • Since the routers are not sharing routing tables, we need to configure a default route to the WestCoast router. The IP address of the WestCoast router is 10.200.200.1/24. 
  8. The final part of the basic configuration of the EastCoast router is to configure the BRI interface and dialer interface.
    • Configure the dialer interface with the IP address 10.200.200.2/24.
    • Configure the Service Profile Identifiers: SPID1=51055580000001, SPID2=51055580010001
    • Configure the encapsulation type to be PPP.
    • For security reasons, configure the authentication to be CHAP.
      To keep the line from staying connected all of the time, configure the idle timeout to be 60 seconds.
    • Lastly, the router needs to know where to dial. Configure the dialer map with the IP address of the WestCoast router(10.200.200.1), the name of the router to be dialed(WestCoast), and the number to dial(5551234).
    • Apply the dialer list to the interface.

    Don't forget the no shutdown command on the interfaces.

  9. Before configuring Weighted Fair Queuing on the routers, test your configurations by pinging the other router. This way you are insuring that your basic configuration is correct before changing it.
  10. Verify current queueing method in use
    • Enter the show interfaces command.

    In the information returned by the router, what does the router say the queueing method is for BRI interface?


  11. We will now be modifying the queuing method. If the queuing method was either FIFO, or WFQ, we will be changing the queuing parameters. We have decided to alter the default congestive discard threshold to 128, this number is the number of messages creating a congestion threshold. After the number of messages reaches 128, messages for high-volume traffic will no longer be queued, until the total of the queue's contents drops below one fourth of the congestive discard threshold (32 for this example). The result is control of high-volume traffic, which would otherwise dominate the bandwidth until it has finished with the complete transfer of data. You will need to issue the fair-queue command on both the physical interface and the dialer interface.

    WestCoast(config)#interface bri0
    WestCoast(config-if)#fair-queue 128

    WestCoast(config)#interface dialer1
    WestCoast(config-if)#fair-queue 128

    EastCoast(config)#interface bri0
    EastCoast(config-if)#fair-queue 128

    EastCoast(config)#interface dialer1
    EastCoast(config-if)#fair-queue 128

    What is the significance of the 128 in the above commands?


  12. Once we have configured the routers, we need to once again verify that the routers can communicate together. Try pinging the other router again to insure that they are communicating.
  13. Finally, we need to check to make sure that the routers are using fair queuing and that it is operating correctly. Issue the following commands and observe the responses from the router.

    WestCoast#show queue bri0
    EastCoast#show queue bri0

    What did the routers respond with?

    WestCoast#sh queue bri 0
    Input queue: 0/75/0 (size/max/drops); Total output drops: 0
    Queueing strategy: weighted fair
    Output queue: 0/1000/64/2158 (size/max total/threshold/drops)
    Conversations 0/2/256 (active/max active/max total)
    Reserved Conversations 0/0 (allocated/max allocated)

    WestCoast#show queueing fair
    EastCoast#show queueing fair

    What did the routers respond with?



    WestCoast#sh queueing fair
    Current fair queue configuration:
    interface BRI0

    Input queue: 0/75/0 (size/max/drops); Total output drops: 0
    Queueing strategy: weighted fair
    Output queue: 0/64/0 (size/threshold/drops)
    Conversations 0/1 (active/max active)
    Reserved Conversations 0/0 (allocated/max allocated)

  14. Optional challenge step to test the operation of WFQ. From the workstation/server connected to the WestCoast router, initiate a large file transfer from the workstation/server connected to the EastCoast router. Now initiate a continuous ping from EastCoast workstation to the WestCoast workstation. Finally initiate a telnet session between the two workstations/servers. Enter show queueing fair command on each of the routers.

What did the router respond with?



WestCoast#sh queue BRI 0 (after testing starts)
Input queue: 0/75/0 (size/max/drops); Total output drops: 2158
Queueing strategy: weighted fair
Output queue: 4/1000/64/2158 (size/max total/threshold/drops)
Conversations 1/2/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)

(depth/weight/discards/tail drops/interleaves) 4/4096/0/0/0
Conversation 202, linktype: ip, length: 1504
source: 10.100.100.2, destination: 10.30.30.2, id: 0x7F3A, ttl: 31,
TOS: 0 prot: 6, source port 1281, destination port 10113


How has this response changed from the first time that you issued the
show queueing fair command?