PRACTICAL INTRODUCTION TO INTERNET TECHNOLOGY

Practical one PACKET DELAY AND LOSS IN INTERNET In this experiment, you will observe real delays and loss inherent in internet. Also all the paths a packet will pass through from source to destination

3 “Real” Internet delays and routes What do “real” Internet delay & loss look like? Traceroute program: provides delay measurement from source to router along end-end Internet path towards destination. For all i: – sends three packets that will reach router i on path towards destination – router i will return packets to sender – sender times interval between transmission and reply. 3 probes

4 “Real” Internet delays and routes 1 cs-gw ( ) 1 ms 1 ms 2 ms 2 border1-rt-fa5-1-0.gw.umass.edu ( ) 1 ms 1 ms 2 ms 3 cht-vbns.gw.umass.edu ( ) 6 ms 5 ms 5 ms 4 jn1-at wor.vbns.net ( ) 16 ms 11 ms 13 ms 5 jn1-so wae.vbns.net ( ) 21 ms 18 ms 18 ms 6 abilene-vbns.abilene.ucaid.edu ( ) 22 ms 18 ms 22 ms 7 nycm-wash.abilene.ucaid.edu ( ) 22 ms 22 ms 22 ms ( ) 104 ms 109 ms 106 ms 9 de2-1.de1.de.geant.net ( ) 109 ms 102 ms 104 ms 10 de.fr1.fr.geant.net ( ) 113 ms 121 ms 114 ms 11 renater-gw.fr1.fr.geant.net ( ) 112 ms 114 ms 112 ms 12 nio-n2.cssi.renater.fr ( ) 111 ms 114 ms 116 ms 13 nice.cssi.renater.fr ( ) 123 ms 125 ms 124 ms 14 r3t2-nice.cssi.renater.fr ( ) 126 ms 126 ms 124 ms 15 eurecom-valbonne.r3t2.ft.net ( ) 135 ms 128 ms 133 ms ( ) 126 ms 128 ms 126 ms 17 * * * 18 * * * 19 fantasia.eurecom.fr ( ) 132 ms 128 ms 136 ms traceroute: gaia.cs.umass.edu to Three delay measurements from gaia.cs.umass.edu to cs-gw.cs.umass.edu * means no response (probe lost, router not replying) trans-oceanic link

INSTALL TRACEROUTE INSTALL THE Visual traceroute program in the folder provided. After installation: explore the software interface to have a feel of the commands available.

Exercise 1 Find the trace route from your computer to : Your school’s website Record and save your observations in files Record and save your observations in files

Exercise 2 Traceroute: to to to Record and save your observations in files How many hops were in each trace route? How many ISP and peering points were in each traceroute? What other useful observations could you see

Practical Two Simulation of internet switching methods: packet-switching and message switching In this practical you will see the way packets are sent over the internet. You will be able to adjust some parameters such as distance, propagation delay, packet size, etc.

Exercise 1 Type the following address into your browser address bar: 536/ cw/index.html first three 1.Play with the first three applets using various parameters of your choice. 2.Record your observations. 3.What more understandings have you gained?

Practical Three DNS SERVER A server that maintains a database of IP address/computer name mappings. The DNS has the responsibility to resolve fully qualified domain names and other host names to IP addresses. In DNS, the clients are called resolvers and the servers are called name servers. WE SHALL USE nslookup UTILITY TO ACCESS DNS SERVER TO OBTAIN IP ADDRESSES WE SHALL USE nslookup UTILITY TO ACCESS DNS SERVER TO OBTAIN IP ADDRESSES

11 requesting host cis.poly.edu gaia.cs.umass.edu root DNS server local DNS server dns.poly.edu authoritative DNS server dns.cs.umass.edu 7 8 TLD DNS server DNS name resolution example Host at cis.poly.edu wants IP address for gaia.cs.umass.edu iterated query: rcontacted server replies with name of server to contact r“I don’t know this name, but ask this server”

12 requesting host cis.poly.edu gaia.cs.umass.edu root DNS server local DNS server dns.poly.edu authoritative DNS server dns.cs.umass.edu 7 8 TLD DNS server 3 recursive query: rputs burden of name resolution on contacted name server rheavy load? DNS name resolution example

nslookup The nslookup utility is used to find out the corresponding IP address of a host name by contacting Internet Domain Name Servers. It also does reverse name lookup and find the host name for a specified IP address. It has two modes: interactive and non-interactive. Interactive mode is used to get information about various hosts and domains or to displays a list of hosts in a domain. Non-interactive mode is used to display just the name and requested information for a host or domain.

Exercise 1 1.Locate nslookup program from the list of programs on your pc. 2.Hint: search for nslookup 3.Run the nslookup program. It is a dos based program 4.Type in the followings and obtain the IP values: i. ii. iii. iv – Try some other web addresses & record your observations

EXERCISE 2 USING WEB BASED TOOLS TO ACCESS DNS SERVERS records TYPE THE FOLLOWING INTO YOUR BROWSER REPEAT STEP 4 OF EXERCISE 1 Run: ping, DNS records, Express for Record your observations Try your hand on DNS Server applet at: k_2/applets/dns/dns.html k_2/applets/dns/dns.html

Practical Four Speed and Bandwidth Test In this practical, you will be able to measure the speed, bandwidth, and performances of your internet connection

INSTALL MY CONNECTION SPEED INSTALL THE my connection speed program in the folder provided. After installation: explore the software interface to have a feel of the commands available such as tools.

Exercise 1 Run application speed Determine the Upload and download speed, maximum bandwidth, quality of service, RTT, and maximum delay of your internet connection. Run application speed Determine the Upload and download speed, maximum bandwidth, quality of service, RTT, and maximum delay of your internet connection.

Exercise 2 Run capacity speed Determine the: Upload and download speed, maximum bandwidth, quality of service, Round Trip Time, and maximum delay of your internet connection.

SUBMISSION SUBMIT YOUR OBSERVATIONS FOR ALL THE PRACTICAL YOU HAVE DONE USING STANDARD LABORATORY REPORT FORMAT. SUBMIT ELECTRONICALLY TO Use your matric number only as the subject heading of the mail SUBMIT YOUR OBSERVATIONS FOR ALL THE PRACTICAL YOU HAVE DONE USING STANDARD LABORATORY REPORT FORMAT. SUBMIT ELECTRONICALLY TO Use your matric number only as the subject heading of the mail