The following table is for your reference as you learn about telnet and FTP:
Term Definition
Client A program you use to request a resource or service from another program called a "server." For example, you may use a client to request a file from a file server. Generally, the client is located on a different computer from the server, often on your own desktop. See "Server." Download Simply put, to "get" a file from a server. To be more specific, it means to transfer files between two computers, usually, to transfer files from a server on a larger computer to a client on a smaller computer. See "Upload." Host A computer, connected to a network, that allows you to log in and use resources. For example, Isis is a host computer you may use for your email service. IP Number Internet Protocol number. The unique number that identifies a computer on the Internet. You can use a computer's name or its IP number when you specify its address. Server A program that "serves up" resources and services you request using your client program. The server is usually located on a "host" computer. "Host" and "Server" are frequently used interchangeably. See "Client." Upload Simply put, to "put" a file onto a server. To be more specific, it means to transfer files between two computers, usually, to transfer files from a client on a smaller computer to a server on a larger computer. See "Download."
We got help with these definitions from the Free On-line Dictionary of Computing at http://wombat.doc.ic.ac.uk/. (If you're not sure what that means, take Introduction to the Internet and the Internet: Browsing class to find out.)
Telnet and FTP are protocols, a set of formal rules for transmitting data. You use these protocols to connect to servers on the Internet for two different purposes:So, you have one protocol for looking at information, and a separate protocol for transferring files. How do you find the files you want to transfer? One way is to use a client program called archie. Telnet, FTP, and archie are interrelated, and are discussed further in this document.
- To log on to an Internet server and look at information there, you use the telnet protocol. For example, you use telnet to log on to the library's server. You cannot download or upload files using telnet.
- To download or upload files, you use the File Transfer Protocol (FTP).
You may already be using telnet to log on to the campus email server, for example, or to log on to hosts that provide public access, such as the library's public information server. To telnet to a host from a PC with a direct Internet connection, you can use a program called Host Presenter, which is in the LAN Workplace program group. You cannot use Host Presenter if you're using a modem, but you can telnet using UNIX commands as discussed later in this document.
To see how Ewain works, try telnetting to the unc library server.Ewain instructions/screens in development
The way you move from screen to screen in a telnet session varies from host to host. You often find this navigation information displayed at the bottom of the screen. Many hosts provide a menu structure that's easy to use, but some do require you to use UNIX commands. If you're having difficulty in a session and can't find help on the screen, try typing help. If you want to exit the session but can't find the command, try typing exit. After you exit from one host session, you may want to telnet to another host using Host Presenter. Select Open Session . . . from the File menu, and complete the pop up window again. When you've completed all your sessions, you can quit Host Presenter by selecting Exit from the File menu.Making a Telnet Connection With the UNIX Command
Once you connect to a host, you can telnet to a different host using the UNIX command "telnet". If you have a direct Internet connection, it's preferable to use Host Presenter instead to conserve Internet resources. If you're using a modem, however, you'll want to use UNIX to telnet to "foreign" hosts. First connect to your campus server with a program such as ProComm or MS-Kermit. Then at the UNIX prompt, type telnet hostname.Telnet's Limitation
You can get access to a great deal of information and services through telnet, but you cannot transfer files. To transfer files, use the File Transfer Protocol (FTP), which is discussed next.FTP
You can use FTP to transfer files between:Anonymous FTP servers allow you to log on and transfer files, even though you don't have an account on the servers. Let's look at some reasons you might use FTP.
- Your computer and a server on which you have an account
- Your accounts on two different servers
- Your computer (or account) and an "anonymous FTP" server
If you have an account on a server on campus, you can use FTP to upload files from your PC to your account. With the file in your account, you might then want to email it, for example. Downloading files through anonymous FTP is a good way to get free software and other types of files. (Note: before you run any software you download, be sure to check it for viruses. When you download text files, however, you don't need to worry about infecting your computer with a virus; viruses are transmitted only through program files.) Some servers also allow the public to upload files to selected directories--which is why you need to be careful about viruses when you download programs.
Two Kinds of FTP
For FTP in Windows95, you can use a package called WSFTP, or use UNIX commands. WSFTP is a microcomputer FTP client that you'll put on your PC's hard drive. Although it can only be used with a direct ("hard-wired") connection (i.e. not with a modem connection), Rapid Filer has distinct advantages over UNIX FTP, the primary one being that you can upload and download files directly to and from your PC. UNIX FTP is a mainframe client, which means that you can connect via modem to your mainframe account and use FTP to upload and download from it. To repeat, when you use UNIX FTP, you are uploading and downloading to and from your mainframe account, not your PC, as you are using Rapid Filer. Both kinds of FTP are discussed below.Windows95 WSFTP
WSFTP instructions/screens in development
FTP Using UNIX Commands
You may want to use UNIX commands to transfer files if, for instance, you're using a modem. The following table lists some commands you'll use:
Command Description ftp ftpservername Opens an FTP session at the server you specify. binary Sets the file transfer type to binary. Critical to the successful transfer of files such as Word documents, graphics, or software packages; also works fine with text files (files that contain only ascii text and no formatting). get filename Transfers the file you specify to your account on the campus server. mget file1 file2 Transfers multiple files you specify to your account on the campus server. ls Lists all the files in your current sub-directory. cd subdirectory Changes the directory. To move back up to a previous level, use "cd .." (note the space). put filename Transfers a file from your account on a server to a directory on another server. mput file1 file2 Transfers multiple files from your account on a server to a directory on another server. pwd Tells you the present working directory. <Ctrl>+h Deletes a character to the left of the cursor (acts as a backspace). Note: use the Ctrl key; don't type the word "Ctrl". help command Displays the definition of a command. Type "help" to see a full list of valid commands. bye Ends the FTP session.Steps for Downloading
Here are the steps for downloading a file using UNIX commands:
- Connect to your campus server.
- At the UNIX prompt, type ftp ftpservername. To use the example from our discussion of Rapid Filer, we type ftp ftp.uwtc.washington.edu. Note: often "ftp" will be the first level of the server name (as it is in this example) in addition to the command you use to establish an ftp connection; be sure that you do not omit it in either case.
- Log on to the FTP server.
If the server is available, the ftp prompt appears.
- If you don't have an account on the server, log on as anonymous. Use your email address as the password.
- If you have an account on the server, log on with your ID and password.
- Find the file you want. Refer to the previous table for commands you'll need. To continue our example:
- To see the name of the current directory, type pwd.
- To change to the Netscape directory, type cd /pub/Windows/WWW.
- To see the files listed in that directory, type ls.
- Type binary to set the file transfer type.
- Type get filename. The file is transferred to your account on the campus server. To get the file in our example, we type get n32311b1.exe.
- To move the file from the campus server to your computer, use Rapid Filer or, if you're on a modem, use zModem or Kermit.
Uploading
Uploading files is a similar procedure. To upload a file, telnet to the campus server from which you want to transfer a file to another server. Note the name of the file you want to transfer. FTP to the target server and log on. Find the directory to which you want to transfer the file. At the FTP prompt, type put filename. The file is transferred.FTP on the World Wide Web
You can also transfer files on the World Wide Web using FTP. Details of the FTP session vary with the browser you use, but generally, you simply point and click to select a file to download. Of course, the file must be available at an FTP server for you to be able to download it. The browser steps you through choices for downloading, depending on your computer setup.
Archie is a client program that searches for files you can download. You provide a search term to archie, and it looks for file and directory names that contain that term on servers around the world. Archie searches only anonymous FTP servers.
Most people don't keep archie software on their desktops. Instead, it's a good idea to telnet to one of the following hosts and use the archie client housed there:
Host Name IP Number State archie.unl.edu 129.93.1.14 NE archie.internic. 198.48.45.10 NJ net archie.rutgers.e 128.6.18.15 NJ du archie.ans.net 147.225.1.10 NY archie.sura.net 128.167.254.179 MD
Try to log on to the archie server nearest you. Archie servers can be busy, so if one doesn't give you access, try another, or try again at a later time.
Let's try a simple archie search. Telnet to an archie server listed, and log on as archie. (Correct typos at the log-in prompt by holding down the Ctrl key and typing h.) Usually you don't have to type a password to access an archie server. You're ready to begin your search when you see this prompt: archie>. To search, type find searchterm. For example, to find the Netscape program we downloaded in our discussion of FTP, we can typefind NetscapeWhile it searches, archie displays information including your place in the search queue (your place in line), and the estimated time it needs to complete your search: As archie finds file and directory names that contain your search term, it displays these "hits" on the screen. For example, archie displayed this information in our search for the term, "Netscape":
Host ftp.uwtc.washington.edu (128.95.202.40) Last updated 08:27 8 Jun 1995 Location: /pub/Mac/Network/WWW DIRECTORY rwxr-xr-x 512 bytes 02:28 7 Jun 1995 Netscape Location: /pub/Windows/WWW DIRECTORY drwxr-xr-x 1024 bytes 23:06 6 Jun 1995 Netscape
Let's examine this message. Archie found the search term at the host ftp.uwtc.washington.edu (IP number 128.95.202.40) in two Locations (paths): /pub/Mac/Network/WWW and /pub/Windows/WWW. We're working in Windows, so, of course, we're interested in the second location. In the line following the location, archie provides details about the files or directories it found with our search term. At this location, it found a DIRECTORY called Netscape.When choosing sites from your list of hits, keep in mind a couple of rules of thumb. Choose a server that's close to you geographically. If you're looking for programs that run in Windows, make sure that the file is either specifically for Windows, or is in a folder that relates to Windows or Pcs, as we did in our example.
If archie finds a large number of sites, it scrolls through the information far too quickly for you to see it all. Therefore, you may want archie to mail the results of a search to your email address. Just typemail your_email_address
You can customize your archie session by changing variables. First, display the current variable settings by typing show at the archie prompt. To change the value of a variable, type set variablename value. For example, to set the maximum number of hits archie reports equal to 10, type set maxhits 10. Archie's on-line help provides more information about variables.
To see archie's help screens, type help at the archie prompt. To see a copy of the complete archie reference manual, type manpage at the archie prompt. This manual is a long document and a good reference, so you'll probably want to mail a copy to yourself using the mail command.
To end your archie session, type bye at the archie prompt. You can then telnet to other sessions, or begin an FTP session to retrieve the files you found.The IAB Data Collection thanks the University of North Carolina for provding the basic layout for these web pages. The original document was a web page from the The Office of Information Technology at The University of North Carolina that has been modified/updated for general use. The information contained in these pages is intended to help beginning internet users to use the World Wide Web (WWW). It is written to help IAB members, State Board Members, and others find and use information on the internet. Please send any comments/suggestions to Ernie_Patterson@unc.edu.