Lab 6.2.1 Observing DNS Name Resolution

Step 1: Observe DNS conversion

  1. Click the Start button, select Run, type cmd, and then click OK. The command prompt window appears.
  2. At the command prompt, type ping http://www.cisco.com. The computer needs to translate http://www.cisco.com into an IP address so it knows where to send the Internet Control Message Protocol (ICMP) packets. Ping is a type of ICMP packet.
  3. The first line of the output shows http://www.cisco.com converted to an IP address by DNS. You should be able to see the effect of DNS even if your school has a firewall that prevents pinging, or if Cisco has prevented people from pinging their web server.396ms           

 

Pinging e144.cd.akamaiedge.net [125.252.192.170] with 32 bytes of data:

Reply from 125.252.192.170: bytes=32  time=  TTL=53

Reply from 125.252.192.170: bytes=32  time=  TTL=53

Reply from 125.252.192.170: bytes=32  time=  TTL=53

Reply from 125.252.192.170: bytes=32  time=  TTL=53

Ping statistics for 125.252.192.170;

Packets: sent = 4, Received = 4, Lost =0 <0% loss>,

Approximate round trip times in milli-seconds :

Minimum = 393ms, Maximum = 775ms, Average = 559ms

  1. Which IP address is shown on the screen?  125.252.192.170
  2. Is it the same as the one shown in the figure?

Ya, sama

Why do you think this occurred?

Karena DNS merupakan database yang menampung semua hostname dari domain yang menunjukkan IP address. Jadi dari manapun kita mengakses domain tersebut, IP address yang di panggil tetap saja sama.

  1. Work together with another student and discuss one or two other instances (besides the ping command) in which the computer would use DNS.

 

Step 2: Verify DNS operation using the nslookup command

  1. At the command prompt, type the nslookup command.

C:\Documents and Setting/dewi>nslookup www.cisco.com

Server : CacheDNS-JKT2.telkom.net.id

Address: 203.130.196.5

Non-authoritative answer :

Name:  e144.cd.akamaiiedge.net

Address: 60.254.176.170

Aliases:  www.cisco.comwww.cisco.com.akadns.net

Geoprod.cisco.com.akadns.net,  www.cisco.com.edgekey.net

http://www.cisco.com.edgekey.net.globalredir.akadns.net

2.What is the default DNS server being used?

Server              : CacheDNS-JKT2.telkom.net.id

Address           : 203.130.196.5

3. Notice how the command prompt changed. This is the NSLOOKUP prompt. From this prompt, you can enter commands related to DNS.

4. At the prompt, type ? to see a list of all the available commands that you can use in NSLOOKUP

mode.

5. Write three commands that you can use with NSLOOKUP.

–   Nslookup host name

perintah ini mengatakan “kirimkan saya IP address dari host”

–   nslookup –type=NS host name

kita memberikan sebuah opsi “-type=NS” dan domain “host name”. Ini menyebabkan nslookup mengirimkan sebuah query untuk sebuah record bertipe NS ke server DNS lokal yang default

–   nslookup host name server DNS

Pada perintah ini, kita mengindikasikan bahwa kita menginginkan query dikirimkan ke server DNS bukan ke server DNS default.

6. At the NSLOOKUP prompt, type www.cisco.com.

7. What is the translated IP address?

IP address yang ditranslate adalah 60.254.176.170

8. Is it the same as the IP address shown with the ping command?

Ya, sama

9. At the prompt, type the IP address of the Cisco web server that you just found. You can use NSLOOKUP to get the domain name of an IP address if you do not know the URL. Using the previous procedures, find an IP address associated with www.google.com.

C:\Document and setting\dewi>nslookup www.google.com

Server            : CacheDNS-JKT2.telkom.net.id

Address          : 203.130.196.5

Non-authoritative answer:

Name:            www.l.google.com

Addresses      : 64.233.181.147, 64.233.181.99, 64.233.181.103, 64.233.181.104, 64.233.181.105, 64.233.181.106

Aliases           : www.google.com

 

 

Step 3: Identify mail servers using the nslookup command

  1. At the prompt, type set type=mx to have NSLOOKUP identify mail servers
  2. At the prompt, type www.cisco.com.

Microsoft Windows XP [Version 5.1.2600]

C:\Documents and Settings\dewi>nslookup

Default Server:  CacheDNS-JKT2.telkom.net.id

Address:  203.130.196.5

 

> set type=mx

> cisco.com

Server:  CacheDNS-JKT2.telkom.net.id

Address:  203.130.196.5

 

Non-authoritative answer:

cisco.com       MX preference = 15, mail exchanger = rtp-mx-01.cisco.com

cisco.com       MX preference = 20, mail exchanger = ams-inbound-a.cisco.com

cisco.com       MX preference = 25, mail exchanger = syd-inbound-a.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-a.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-b.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-c.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-d.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-e.cisco.com

cisco.com       MX preference = 10, mail exchanger = sj-inbound-f.cisco.com

 

cisco.com       nameserver = ns1.cisco.com

cisco.com       nameserver = ns2.cisco.com

sj-inbound-b.cisco.com  internet address = 128.107.234.205

sj-inbound-c.cisco.com  internet address = 128.107.234.206

sj-inbound-d.cisco.com  internet address = 128.107.243.13

sj-inbound-e.cisco.com  internet address = 128.107.243.14

sj-inbound-f.cisco.com  internet address = 128.107.234.207

rtp-mx-01.cisco.com     internet address = 64.102.255.47

ams-inbound-a.cisco.com internet address = 64.103.36.153

syd-inbound-a.cisco.com internet address = 64.104.252.248

3. What is the primary name server, the responsible mail address, and the default Time to Live (TTL)?

Primary name server yaitu nameserver = ns1.cisco.com

4. At the prompt, type exit to return to the regular command prompt.

5. At the prompt, type ipconfig /all.

6. Write the IP addresses of all the DNS servers that your school uses.

7. Type exit to close the command prompt window.

Step 4: Reflection

  1. If your school did not have a DNS server, what effect would this have on your use of the Internet?

Mungkin jika tidak ada DNS server, kita akan sulit sekali menghafalkan setiap IP address untuk masing-masing domain. Itu di sebabkan tidak ada penerjemah dari nama domain ke IP address.

2. Some companies do not dedicate a single server for DNS. Instead, the DNS server provides other functions as well. Which functions do you think might be included on a DNS server? Use the ipconfig /all command to help you with this.

 

Lab 6.2.3 Exploring FTP

Step 1: Examine FTP from the command prompt

  1. Click the Start button, select Run, type cmd on the command line, and then click OK.
  2. At the prompt, type ftp to start the FTP application. The prompt changes.
  3. From the ftp prompt, type ? to see a list of the commands that can be used in this mode.
  4. List three FTP commands.

–   Help get

–   Help send

–   Help recv

5. At the prompt, type help put to see a short description of the put command.

6. What is the purpose of the put command?

Put difungsikan untuk memasukkan atau meletakkan suatu file kedalam server.

7. Use the help command again to get the purpose of the get, send, and recv commands.

get  digunakan untuk mendapatkan atau mengambil sebuah file dari server atau juga mendownload

send digunakan untuk mengirimkan suatu file ke server atau juga mengupload.

recv adalah perintah yang member informasi tentang penerimaan file dari server.

8. Partner with another student. Using procedures demonstrated in previous labs, write down the names and IP addresses of each partner computer. It is very important to get these names correct. Some FTP applications allow you to use either the IP address or the computer name.

Computer 1: 192.168.10.1

Computer 2:  192.168.10.2

 

Step 2: Use a GUI FTP client or web browser

  1. If you are using a web browser as the FTP client, open the web browser and type ftp://ip_address_of_FTP_server. If the FTP server is configured to use an anonymous userID, connect directly to the FTP server. Using the FTP client, download an available file from the server.
  2. If you are using a GUI FTP client, open the application. For most FTP clients, you must configure a new connection by giving it a name, the IP address of the FTP server, and a username and password. You may have to type anonymous if the FTP server allows this type of connection. Some applications have a checkbox that allows an anonymous login. When you have configured the connection, connect to the FTP server and download a file.
  3. What is the name of the file you downloaded from the FTP server?

Nama file yang didownload adalah Alamat IP-versi 6

4. List one example of when FTP might be beneficial to a computer technician.

Salah satu contoh kegunaan FTP untuk teknisi computer adalah, ketika kita membutuhkan sebuah data atau ingin memberikan data kepada computer lain kita tidak perlu susah-susah untuk mengkopi data dari computer satu dan menyalinnya ke computer lain, tapi dengan file transfer protocol kita bisa sharing data dengan mudah dengan menggil IP dari computer source ke computer destination.

 

Step 3: (Optional) Use both an FTP server and client

a. If you control both the FTP server and client, practice sending files to and getting files from the client and the server.

b. Show your transferred files to another group of students.

c. Close the FTP server and client applications.

 

 

Lab 6.2.4 Configuring an Email Client

Step 1: Open Microsoft Outlook

  1. From the Start menu, select All Programs. Locate the Microsoft Office software.
  2. Select Microsoft Office Outlook as the email program. If your computer does not have the Microsoft Office software, there are many free email software packages available on the Internet. Search the Internet to find a free email client that can be installed on your computer. The following instructions may vary depending on your email client.

Step 2: Set up an email account

  1. When you first start Microsoft Outlook, a screen appears with Email Upgrade Options. You can choose to import email messages or address books from another account. Because this is your first email account, select the Do Not Upgrade button
  2. The next screen is the Email Accounts screen where you are asked if you want to configure an email account. Click Yes.
  3. If Outlook has already been installed and setup for e-mail previously, you can start the Outlook application and click Tools, E-Mail Accounts and then select View or change existing e-mail account to see how the existing account is set up.

Step 3: Enter POP3 e-mail account information

  1. The next screen requires the user of the new account to fill in information. Enter your name and email address. Your can get your email address from your Internet provider.

NOTE: If you do not have a real ISP email account, this step can be treated as a simulation. Just enter the information requested to become familiar with the process of creating an email account.

  1. Enter your server information. Contact your Internet provider to locate the server information for the incoming and outgoing mail servers. Usually Internet providers put this information on their website in their help section.
  2. What is your incoming (POP3) mail server?

 

Sebuah server yang mendukung klien POP menerima dan menyimpan pesan yang ditujukan untuk para penggunanya. Ketika klien terhubung ke server email, pesan akan didownload ke klien. Secara default, pesan yang tidak disimpan di server setelah mereka telah diakses oleh klien. Klien menghubungi server POP3 pada port 110.

3. What is your outgoing (SMTP) mail server?

SMTP digunakan oleh klien email untuk mengirim pesan ke server email lokal. Server lokal kemudian memutuskan jika pesan itu diperuntukkan untuk kotak surat lokal atau jika pesan ditujukan ke kotak surat pada server lainnya.

Jika server telah mengirim pesan ke server yang berbeda, SMTP digunakan antara dua server juga. SMTP permintaan dikirim ke port 25.

  1. Listen
  2. Read phonetically

4. Enter your username and password. Do not check the box to remember your password. This option is used when only one person uses the computer. If anyone else were to use the computer, they could easily gain access to all of the information in your email.

5. Click the Test Account Settings button. If everything is correct, the screen displays that the test was successful. If not, correct your information and try again.

NOTE: If this is a simulation, the test will not be successful and you can go to Steps 4 and 5

6. Test your new account by sending an email to a friend in class.

 

 

Step 4: (Optional) Add another account or change an account

  1. Open Microsoft Outlook. From the Tools menu, select Email Accounts.
  2. In this screen, you can add another email account or you can change information in an existing account

 

Step 5: Reflection

  1. What are the advantages or disadvantages to using email over regular postal mail?

–   Keuntungan menggunakan regular  postal mail adalah dari segi keamanan lebih tinggi karena lebih jelas pemilik account yang mengirim dan yang akan menerima, dan lebih di akui ke absahan surat yang kita kirimkan karena ternasuk jenis surat elektronik.

–   Kelemahannya adalah surat yang dikirim menggunakan  regular postal mail terkadang lama di jawab oleh penerima, karena terjadi tidak real time atau terjadi pada saat ke dua penerima atau pengirim belum tentu dalam keadaan online. Jadi bisa saja penerima tidak membuka accountnya dalam kurun waktu tertentu.

2. What are the advantages or disadvantages to using email over an instant messaging program?

–   Keuntungannya yaitu pada pengiriman data dapat dilakukan secara real-time dan reponsif.  pengirim dapat langsung menerima balasan atau respon dari penerima data jika dalam keadaan online. Data dapat dikirim baik dalam keadaan online maupun offline.

–   Kelemahannya yaitu

  1. data tidak tersimpan deserver
  2. Setiap data yang telah terkirim, baik data teks, file, maupun streaming, akan segera terhapus dari server. Hanya data teks saja yang bisa disimpan dalam log komputer lokal.
  3. Pengiriman data rentan mengalami kegagalan.
  4. Pengiriman data nonkonteks mengharuskan pihak-pihak yang bersangkutan dalam keadaan online.

3. With a partner, discuss five (5) recommendations for email etiquette that should be considered when emailing friends and business colleagues.

–   Email harus disertai nama pengirim dan identitas lainnya

–   Email harus disertai nama tujuan/ penerima

–   Email harus diberi judul/ subject agar penerima dapat mengerti tujuan surat sebelum di baca.

–   Email hendaknya menggunakan bahasa yang baik

–   Lima menit antara menerima dan membalas email

–   Tulis isi email dengan jelas.

–   Tuliskan email secara pendek dengan kata-kata yang baik.