Packet Tracer Activity: Exploring Network QoS Jaskaran Kalsi, 1st October 2009
Introduction Quality of Server (QoS) is a method of providing better service for selected traffic types over various types of packet-switched networks. QoS provides a method for determining which traffic should be given priority on a network segment. For this exercise your task will be to complete the configuration on the QoS_Router to use QoS to mark EIGRP, Telnet, SSH, and HTTP traffic that exits interface Serial 0/0/0. The policy map that you will apply sets the IP precedence field to 7 for critical packets (EIGRP), 5 for interactive packets (Telnet and SSH), and 3 for web traffic (HTTP). All other traffic is left as unmarked in the default group. Important note: All device passwords are set to cisco
Objectives Your task is to complete the network design; install various devices, complete the configuration, and monitor the network for Quality of Service (QoS). Familiarize your use of Packet Tracer and explore the QoS capabilities of version 5.2/ A full list of tasks detailing the configuration which must be applied has been developed and is available below.
Lab Topology Once you have completed all network configurations, your topology should match the network shown below.
Tasks Cable and Configuration Please complete the below tasks to complete the physical design of the network… 1. Drag and drop a PC onto the physical work space in Packet Tracer. Install this PC connecting to “QoS_Router” port Fa0/0. Label this PC “Host 1”. Apply the following configuration: a. IP Address - 10.1.1.200 b. Subnet Mask - 255.255.0.0 c. Default Gateway - 10.1.1.1 2. Drag and drop another PC onto the physical work space in Packet Tracer. Install this PC connecting to “R3” port Fa0/0. Label this PC “Host 2”. Apply the following configuration: a. IP Address - 200.200.200.20 b. Subnet Mask - 255.255.255.0 c. Default Gateway - 200.200.200.1
Configuration Please complete the below step to configure ‘QoS_Router’ for packet marking…
Step 1: Apply the following configuration to create a class-map which marks all eigrp packets as critical: QoS_Router(config)#class-map match-all critical QoS_Router(config-cmap)#match protocol eigrp
Step 2: QoS_Router has been preconfigured with a policy map named ‘markingpolicy’. You need to apply the following configuration to create the precedence level for the class-map which you have just created: QoS_Router(config)#policy-map markingpolicy QoS_Router(config-pmap)#class critical QoS_Router(config-pmap-c)#set precedence 7
Step 3: You have now completed the steps to configure a class-map marking all eigrp packets as critical and you have also set the precedence level to 7. The next task is to apply the policy-map which you have created onto an interface. In this case the policy-map will be applied to S0/0/0 of QoS-Router, hence all interesting traffic will be marked as it passes through: QoS_Router(config)#interface s0/0/0 QoS-Router(config-if)#service-policy output markingpolicy
Test Packet Marking In order to ensure that the configuration applied is functioning as required, it is important to test the network for Quality of Service. Firstly, issue the show policy-map interface serial0/0/0 command on QoS_Router. You should expect to see an output as follows:
Since Telnet traffic is set to be marked, and as yet no interesting traffic has been detected, no packets have been marked.
Important Note: Since there has been no web (http) traffic sent, no packets have been detected or marked.
Use the Simulation mode to observe the packet forwarding. The QoS stamps on EIGRP packets and Telnet packets have different colours since they're marked with different precedence. ICMP packets don't have the QoS stamps on them since they don't match the QoS match protocol list.
Now generate some interesting traffic by attempting to Telnet from Host 1 to Router R3 (172.16.23.3) within Simulation Mode:
Note that all passwords on routers are set to cisco. Once a successful Telnet session has been initiated, exit the session and return back to the QoS_Router. Again, issue the command show policy-map interface s0/0/0 on QoS_Router, observe the output.
Since Telnet traffic is set to be marked, and possesses a precedence value of 5, the output shows that Telnet packets have been marked.
By activating the ‘Simulation Mode’ of QoS_Router, you should be able to see the various types of packets travelling across the network. By default, you should see many EIGRP packets being exchanged between the routers. With Telnet, visually you should also see Telnet packets being sent across the network; however, observing closely within the ‘Event List’ you should be able to see the TCP authentication handshake packets as well as Telnet packets. Looking further in detail at the QoS_Router, once interesting traffic has been generated, you should see the values of ‘marked packets’ increase.
Congratulations you have now successfully completed the Packet Tracer Activity!
Upon completion you have successfully completed the following objectives… 1. 2. 3. 4. 5. 6. 7. 8.
To use and work with the Packet Tracer v5.2 GUI. Be able to select appropriate devices & network media and place it within the Packet Tracer work area. Successfully connect the devices to create a LAN. Configure wired PC’s to connect to a LAN and communicate with routing devices. Apply network QoS marking traffic techniques. Monitor network traffic using Packet Tracer’s Simulation Mode. Generate interesting traffic within a network. Identify QoS marked traffic.
We hope you enjoyed the activity and gained a valuable insight into the functions of Packet Tracer. Why not try this in your laboratory as a student learning exercise?
Comments/queries are most welcome; please contact…. Jaskaran Kalsi Assoc. Technical Manager Europe & Central Eastern Europe
[email protected]
