Lab 4.3.4 Exploring Network QoS
Step 1: Cable and configure the network
a. Connect and configure the devices in accordance with the given topology and configuration.
1)
2)
Routing will have to be configured across the serial WAN link to establish data communications.
Configure Telnet access on each router.
b. Ping between Host1 and Discovery Server to confirm network connectivity.
1) Confirm Application Layer connectivity by telnetting from R2 to R1.
2) Troubleshoot and establish connectivity if the pings or Telnet fail.
c. After confirming the initial configurations, maintain a console terminal session connection with R2.
Step 2: Examine priority queue commands Configuring Priority Queueing
Configuring priority queueing (PQ) has two required steps and an optional third step:
1. Define the priority list (Required)
2. Assign the priority list to an Interface (Required)
3. Monitor priority queueing lists (Optional)
A priority list contains the definitions for a set of priority queues. The priority list specifies which queue a
packet will be placed in and, optionally, the maximum length of the different queues. To perform queueing
using a priority list, you must assign the list to an interface. The same priority list can be applied to multiple interfaces. Alternatively, you can create many different priority policies to apply to different interfaces.
Defining the Priority List
The priority list is defined by:
1. Assigning packets to priority queues
2. Specifying the maximum size of the priority queues (Optional)
Packets are assigned to priority queues based on the protocol type and the interface where the packets enter the router. The priority-list commands are read in order of appearance until a matching protocol or interface type is found. When a match is found, the packet is assigned to the appropriate queue and the search ends. Packets that do not match other assignment rules are assigned to the default queue. The following global configuration mode commands are used to specify in which queue a packet is placed. The command format is priority-list list-number Use a list-number of 1 and note the options available.
a. Enter the following command and note the options available.
FC-CPE-1(config)#priority-list 1 ?
________ default Set priority queue for unspecified datagrams
________ interface Set priorities for packets from a named interface
________ protocol priority queueing by protocol
________ queue-limit Set queue limits for priority queues
b. Note some of the protocol options available.
FC-CPE-1(config)#priority-list 1 protocol ?
________ arp IP ARP
________ bridge Bridging
________ cdp Cisco Discovery Protocol
________ compressedtcp Compressed TCP (VJ)
________ http HTTP
________ ip IP
________ llc2 llc2
________ pad PAD links
________ pppoe PPP over Ethernet
________ snapshot Snapshot routing support
c. Note the IP protocol options available.
FC-CPE-1(config)#priority-list 1 protocol ip ?
________ high
________ medium
________ normal
________ low
d. Note the HTTP protocol options available.
FC-CPE-1(config)#priority-list 1 protocol http ?
________ high
________ medium
________ normal
________ low
e. Note the IP protocol high priority options available.
FC-CPE-1(config)#priority-list 1 protocol ip high ?
________ fragments Prioritize fragmented IP packets
________ gt Prioritize packets greater than a specified size
________ list To specify an access list
________ lt Prioritize packets less than a specified size
________ tcp Prioritize TCP packets ‘to’ or ‘from’ the specified port
________ udp Prioritize UDP packets ‘to’ or ‘from’ the specified port
________ <cr>
f. Note the IP protocol high priority TCP options available.
FC-CPE-1(config)#priority-list 1 protocol ip high tcp ?
________ <0-65535> Port number
________ domain Domain Name Service (53)
________ echo Echo (7)
________ ftp File Transfer Protocol (21)
________ ftp-data FTP data connections (20)
________ irc Internet Relay Chat (194)
________ nntp Network News Transport Protocol (119)
________ pop3 Post Office Protocol v3 (110)
________ smtp Simple Mail Transport Protocol(25)
________ telnet Telnet (23)
________ www World Wide Web (HTTP, 80)
Step 3: Configure an example priority queue
From the global configuration mode, issue the following commands.
FC-CPE-1(config)#priority-list 1 protocol http high
FC-CPE-1(config)#priority-list 1 protocol ip normal tcp ftp
FC-CPE-1(config)#priority-list 1 protocol ip medium tcp telnet
What do these commands establish?
Sebuah daftar prioritas (nomor “1″) yang menetapkan paket HTTP yang akan ditandai sebagai prioritas tinggi, paket FTP rendah prioritas, dan Telnet paket sebagai prioritas menengah.
Step 4: Assign the priority list to an interface
a. From the global configuration mode, issue the following commands to assign the priority list to interface serial 0/1/0.
FC-CPE-1(config)#int s0/1/0
FC-CPE-1(config-if)#priority-group 1
b. Confirm the priority list configuration. From the privileged EXEC mode, issue the show runningconfig
command.
Which statements in the configuration show that the priority list has been configured and applied correctly?
interface Serial0/1/0
ip address 10.10.0.2 255.255.255.252
priority-group 1
priority-list 1 protocol http high
priority-list 1 protocol ip normal tcp ftp
priority-list 1 protocol ip medium tcp telnet
c. Confirm that issuing the show queueing priority command from the privileged EXEC mode
produces the following output:
FC-CPE-1#show queueing priority
Current DLCI priority queue configuration:
Current priority queue configuration:
List Queue Args
1 high protocol http
1 normal protocol ip tcp port ftp
1 medium protocol ip tcp port telnet
Step 5: Examine the priority queues operation
a. On Host1, launch a web browser and enter the URL http://172.17.1.1 to access the web services configured on the server.
b. Use FTP to download a file. On Host1, launch a new web browser window and enter the URL ftp://172.17.1.1, or from the command line issue ftp 172.17.1.1
c. Download a large file from the server; for example, the Thunderbird setup program file.
d. From the privileged EXEC mode, issue the following command:
FC-CPE-1#show queueing interface s0/1/0
Output similar to this should be displayed:
Interface Serial0/1/0 queueing strategy: priority
Output queue utilization (queue/count)
high/94 medium/0 normal/106759 low/0
Note the packet count for each queue:
High __________ Medium __________ Normal __________ Low __________
e. Initiate a Telnet session from R2 to R1 and issue some show commands on R1.
f. Close the Telnet session.
g. Issue the following command from the R2 privileged EXEC mode:
FC-CPE-1#show queueing interface s0/1/0
Note the packet count for each queue:
High __________ Medium __________ Normal __________ Low __________
What is the significant difference when compared to the previous output form this command in Step 5d?
Antrian Menengah sekarang memiliki jumlah paket, ini adalah prioritas yang ditugaskan untuk paket Telnet.
Step 6: Determine the priority queue requirements for the case study
a. Using the FilmCompany case study, what would you expect the priority queue requirements to be?
b. Discuss and compare your priorities with other students.
c. Amend your priority list statements to include traffic associated with the proposed network upgrade.
Step 7: Clean up
Erase the configurations and reload the routers and switches. Disconnect and store the cabling. For PC hosts that are normally connected to other networks (such as the school LAN or to the Internet), reconnect the appropriate cabling and restore the TCP/IP settings.
Challenge
The following privileged EXEC command displays the contents of packets inside a queue for a particular
interface:
show queue interface-type interface-number
However, in this lab, it is not likely that sufficient data traffic was generated at one time for the interface
queues to hold packets long enough to be inspected. Discuss how a network has to be load tested to ensure that all traffic priorities are met.
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