Objectives
• Observe the conversion of a URL to an IP address.
• Observe DNS lookup using the nslookup command.
Background / Preparation
Domain Name System (DNS) is invoked when you type a Uniform Resource Locator (URL), such as http://www.cisco.com, into a web browser. The first part of the URL describes which protocol is being used. Common ones are HTTP (Hypertext Transfer Protocol), HTTPS (Hypertext Transfer Protocol over Secure Socket Layer), and FTP (File Transfer Protocol). DNS uses the second part of the URL, which in this example is www.cisco.com. DNS translates the domain name (like www.cisco.com) to an IP address in order to allow the source host to reach the destination host.
Work in pairs to complete this lab.
The following resources are required:
• Windows-based computer with Internet connectivity
• Access to the Run command
Step 1: Observe DNS conversion
a. Click the Start button, select Run, type cmd, and then click OK. The command prompt window appears.
b. At the command prompt, type ping www.cisco.com. The computer needs to translate 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.
c. The first line of the output shows 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.
d. Which IP address is shown on the screen? IP address yang ditampilkan ialah 60.254.168.170
e. Is it the same as the one shown in the figure?yes.Why do you think this occurred? Hal ini terjadi karena CISCO memiliki system DNS sehingga alamat cisco meskipun diakses dari computer yang berbeda alamat IP akan tetapi alamat DNS pada CISCO telah teregritasi pada alamat khusus di internet.
f. Work together with another student and discuss one or two other instances (besides the ping command) in which the computer would use DNS. Selain ping perintah lain pada kokmputer yang menggunakan DNS ialah nslookup
Step 2: Verify DNS operation using the nslookup command
a. At the command prompt, type the nslookup command.
b. What is the default DNS server being used?www.unp.ac.id
c. Notice how the command prompt changed. This is the NSLOOKUP prompt. From this prompt, you can enter commands related to DNS.
d. At the prompt, type ? to see a list of all the available commands that you can use in NSLOOKUP mode.
e. Write three commands that you can use with NSLOOKUP= contoh tiga perintah yang bisa digunakan pada nslookup adalah:
1. set type=all
nslookup dengan set type=all. bertujuan untuk melihat name server pada suatu domain.
2. set type=mx
nslookup dengan set type=mx. Bertujuan untuk mengetahui Mail eXchangernya.
3. set type=soa
nslookup dengan set type=soa. Bertujuan untuk mengetahui Start Of Authority nya.
f. At the NSLOOKUP prompt, type www.cisco.com.
g. What is the translated IP address? 60.254.168.170
h. Is it the same as the IP address shown with the ping command?sama.
i. 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.
Ip address yang terkait dengan google ialah : 64.233.181.103, 64.233.181.104, 64.23.181.105, 64.233.181.99 , 64.233.181.147 dan 64.233.181.99
Step 3: Identify mail servers using the nslookup command
a. At the prompt, type set type=mx to have NSLOOKUP identify mail servers.
b. At the prompt, type www.cisco.com.
c. What is the primary name server, the responsible mail address, and the default Time to Live (TTL)?
Nama server : e144.cd.akaiemdge.net
Address : 60.254.168.170
Aliases : www.cisco.com, www.cisco.com.akands.net
d. At the prompt, type exit to return to the regular command prompt.
e. At the prompt, type ipconfig /all.
f. Write the IP addresses of all the DNS servers that your school uses?. 10.1.1.3
g. Type exit to close the command prompt window. CCNA Discovery
Step 4: Reflection
a. If your school did not have a DNS server, what effect would this have on your use of the Internet? Jika tidak memiliki alamat DNS maka situs internet pada sekolah kita maka situs sekolah itu dianggap tidak terdaftar karena tidak teregistrasi.
b. 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
Objective
• Demonstrate how to use FTP from the command prompt and GUI. Background / Preparation File Transfer Protocol (FTP) is part of the TCP/IP suite. FTP is used to transfer files from one network device to another network device. Windows includes an FTP application that you can execute from the command prompt. There are also many free GUI versions of FTP that you can download. The GUI versions are easier to use than typing from a command prompt. When using FTP, one computer is normally the server and the other computer is the client. When accessing the server from the client, you need to provide a username and password. Some FTP servers have a userID named anonymous. You can access these types of sites by simply typing “anonymous” for the userID, without a password. Usually, the site administrator has files that can be copied but does not allow files to be posted with the anonymous userID. If your class does not have an FTP server available, you can download and install a freeware version, such as Home FTP Server or Cerberus FTP server. The FTP Server on a computer running the CCNA Discovery Live CD may also be used. Another computer will act as the FTP client by using FTP from the command line, a web browser, or download a freeware version of an FTP client, such as SmartFTP Client or Core FTP LE client. Work in teams of two to complete this lab.
The following resources are required:
• Windows-based computer with an FTP client
• FTP server (Existing FTP server, downloaded freeware, or use Live CD)
Step 1: Examine FTP from the command prompt
a. Click the Start button, select Run, type cmd on the command line, and then click OK.
b. At the prompt, type ftp to start the FTP application. The prompt changes.
c. From the ftp prompt, type ? to see a list of the commands that can be used in this mode.
d. List three FTP commands.
ls Mendaftar berkas-berkas
cd
bin Menentukan mode transfer biner
e. At the prompt, type help put to see a short description of the put command.
f. What is the purpose of the put command?
g. Use the help command again to get the purpose of the get, send, and recv commands.
get pada ftp server digunakan untuk mendownload berkas
send Mengirim file yang berada dalam komputer lokal ke komputer server yang sedang di-remote
recv Mengcopy file yang ada di remote computer ke dalam computer local
NOTE: The original FTP commands were PUT to send a file to an FTP server and GET to download a file from the FTP server. You also had to select ASCII or binary file mode. If you download a binary file in ASCII mode it could end up being corrupted. Some of the newer graphical programs now use send and receive in their place.
h. 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: __________________________________________________________________
Computer 2: __________________________________________________________________
Step 2: Use a GUI FTP client or web browser
a. 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.
b. 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.
c. What is the name of the file you downloaded from the FTP server? ______________________
d. List one example of when FTP might be beneficial to a computer technician. _______________
____________________________________________________________________________
____________________________________________________________________________
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
Objectives
• Set up an email client.
• Send and receive mail from a mail server.
• Add an email account or change an existing one.
Background / Preparation
An email application gives the user the ability to send and receive messages from another user located on the same local network or on the Internet. The messages are sent by the sending client and stored on an email server. Another email client with a mailbox on the server can then access the server at any time to receive stored messages that are destined for that client.
The following resources are required:
• Windows-based computer with Internet connectivity
• Microsoft Outlook or other email client software
Step 1: Open Microsoft Outlook
a. From the Start menu, select All Programs. Locate the Microsoft Office software.
b. 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
a. 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.
b. The next screen is the Email Accounts screen where you are asked if you want to configure an email account. Click Yes.
c. 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
a. 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.
b. 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.
c. What is your incoming (POP3) mail server? POP3 (Mail server)
d. What is your outgoing (SMTP) mail server? (SMTP) mail server
e. 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.
f. 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.
g. Test your new account by sending an email to a friend in class.
Step 4: (Optional) Add another account or change an account
a. Open Microsoft Outlook. From the Tools menu, select Email Accounts.
b. In this screen, you can add another email account or you can change information in an existing account.
Step 5: Reflection
a. What are the advantages or disadvantages to using email over regular postal mail? Keuntungan dengan akun yang mudah dibuat dan gratis. Info dari mail server bisa delink kan dengan smartphone. Sedangkan kerugian kapasitas atau kuota email terbatas, banyak pesan yang dianggap spam.
b. What are the advantages or disadvantages to using email over an instant messaging program?
Keuntungannya koneksi atau komunikasi terjadi secara langsung, kerugiannya aplikasi yang diberikan masih minim.
c. With a partner, discuss five (5) recommendaions for email etiquette that should be considered when
emailing friends and business colleagues.
1. Jangan melakukan SPAM.
2. Hapuslah pesan reply yang tidak perlu.
3. Bersabarlah dalam menunggu "reply".
4. Benahi susunan email "forwards" anda
5. Gantilah "Subject" atau judul email bila topik pembicaraan anda berubah.
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