CCNA LABSKILL CHAPTER6
Posted October 17, 2010on:
Lab 6.2.1 Observing DNS Name Resolution 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 http://www.cisco.com. DNS translates the domain name (like http://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 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. c. 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. CCNA Discovery Networking for Home and Small Businesses.
d. Which IP address is shown on the screen?
Jawab: IP Addressnya adalah: 220.127.116.11
e. Is it the same as the one shown in the figure? Why do you think this occurred?
Jawab: Setrelah dilakukan ping, maka ada perbedaan alamat IP Address pada contoh dengan yang percobaan ping yang dilakukan. Ini terjadi karena IP Address tiap PC berbeda.
f. 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
a. At the command prompt, type the nslookup command.
b. What is the default DNS server being used?
Jawab: Default DNS yang digunakan: cacheDNS-JKT
telkom.net.id IP Addressnya : 18.104.22.168
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.
Jawab: -Nslookup host name
-nslookup host name server DNS
-nslookup –type=NS host name
f. At the NSLOOKUP prompt, type http://www.cisco.com.
g. What is the translated IP address?
Jawab: IP Addressnya: 22.214.171.124
h. Is it the same as the IP address shown with the ping command?
Jawab: IP Address pada proses ping tidak sama dengan IP Address pada percobaan nslookup pada DNS.
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.
Alamat IP Addressnya: 126.96.36.199
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 http://www.cisco.com.
c. What is the primary name server, the responsible mail address, and the default Time to Live (TTL)?
Jawab: Nama server primary nya adalah ns1.cisco.com
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.
g. Type exit to close the command prompt window.
Step 4: Reflection
a. If your school did not have a DNS server, what effect would this have on your use of the Internet?
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.
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?
Jawab: Tujuan dari put command adalah mengupload file atau data oleh server.
g. Use the help command again to get the purpose of the get, send, and recv commands. Jawab: get : Untuk mendownload file atau data oleh client ke server.
send : Menerima satu file dari server.
recv : Untuk mengetahui data apa yeng telah didownload.
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.
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
• 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?
Jawab: POP3 tidak dimaksudkan untuk menyediakan operasi manipulasi mail yang ada di server secara luas. Pada POP3, mail diambil dari server dan kemudian dihapus (bisa juga tidak dihapus). Segala sesuatu tentang protokol POP3 ini dibahas dalam RFC (Request For Comment) 1725. Protokol yang lebih tinggi dan lebih kompleks, yaitu IMAP4, dibahas dalam RFC 1730.
d. What is your outgoing (SMTP) mail server?
Jawab: SMTP (Simple Mail Transfer Protocol) merupakan salah satu protokol yang umum digunakan untuk pengiriman surat elektronik di Internet. Protokol ini dipergunakan untuk mengirimkan data dari komputer pengirim surat elektronik ke server surat elektronik penerima. Protokol ini timbul karena desain sistem surat elektronik yang mengharuskan adanya server surat elektronik yang menampung sementara sampai surat elektronik diambil oleh penerima yang berhak.
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.
Step 5: Reflection
a. What are the advantages or disadvantages to using email over regular postal mail?
Jawab: Keuntungannya adalah:
- Keamanan pesan yang dikirim lebih terjaga, karena pesan yang dikirim langsung dari sumbernya.
- Ketika penerima pesan mereplay pesan yang dikirim oleh pengirim pesan maka kemungkinan balasan dibaca tidak pada saat yang bersamaan dengan pengiriman pesan.
- b.What are the advantages or disadvantages to using email over an instant messaging program?
Jawab: Keuntungannya adalah:
- Pesan yang dikirim bersifat real time, dapat dibaca pada waktu yang sama karena dalam keadaan online.
- Antara pengirim dan penerima pesan belum tentu memakai account yang asli karena bersifat online.
- c.With a partner, discuss five (5) recommendations for email etiquette that should be considered when emailing friends and business colleagues.
- Isi pesan seharusnya singkat, padat dan jelas
- Isinya harus sesuai dengan topic pembicaraan
- Harus bisa membaca keadaan lawan
- Memakai bahasa yang sopan dan sesuai
- Membalas pesan yang diterima seharusnya deadline.