TELNET [port 23]

Telnet is the lifeblood of UNIX servers connected to the Internet. UNIX is primarily a command line driven operating system, and behaves like a faster, more powerful, and multitasking MS-DOS. Telnet is a means to log into a UNIX server across the Internet, as though you were sitting directly at a keyboard connected to the server itself.

The command line, text interface to UNIX works through a tool called a shell. The shell is what takes your commands and sends them to the operating system itself to be carried out. The shell you will use by default on MediaHostNet servers is BASH [Bourne-again shell] Unix commands are notably cryptic, it has been said that Unix IS a user- friendly operating system, it users just very choosy about who its friends are!

UNIX actually has an extremely advanced graphical interface (X-windows) that behaves as a graphical version of telnet. What telnet can do:

• Execute files - You can run programs you've compiled, or programs already on the server. Or test the execution of PERL scripts, or other CGI files.
• Create/Edit files - You may use file editing programs such as pico and vi to edit and compose files.
• Send/Receive Email - Using pine you can both read and compose e-mail for any mail account. To login to any mail account using pine, just telnet to your domain using the login and password for the POP account.
• Change File Permission - You may modify file permissions using the chmod command. Further details in Chapter 2: The Unix File System.

First you must obtain a telnet client. Although there is a basic telnet.exe that comes with Windows, it is exceedingly primitive and lacks functionality that will ease your telnet experience. Any good shareware site will have many telnet clients listed for Windows/Mac etc.

Before logging in take the time to configure your telnet client to use the correct terminal type for the MediaHostNet servers. Doing this will make the output of your telnet session much more readable. Suggested terminal types ['terminal emulation' in some clients] are VT100 and VT220, enable ANSI color if this option is present.

To log in requires three things: hostname, login ID (user name) and password. Your hostname may be your domain name, or your account's IP address. IP address is recommended as you will connect slightly faster.

 Open a connection to your site. you will be presented with a screen like this:

Trying 66.92.214.210...

Connected to mediahostnet.com.

Escape character is '^]'.



Red Hat Linux release 6.1 (Cartman)

Kernel 2.2.14 on an i686

login: someone

Password:

You have new mail.

someone@someone.mediahostnet.com [~]#

This is an example of a successful telnet login. The machine is now ready to accept commands. Most commands are similar to what some of you may recall from MS-DOS.

dir or ls - List the current files for a given directory

cd - Change directory

pico - A simple text editing program

pine - Launch a telnet based mail program

lynx - Launch a text based web browser

chmod - Modify file permissions

rm - Remove [delete] a file

These are but a few examples of the commands and functions which can be done through your shell accounts. Please review our Terms of Use before attempting to run any background process's. NOTE: Running irc programs from a shell will result in termination of your entire account.

SSH [Secure SHell]

SSH [Secure Shell] is very much like telnet, with one large difference; unlike telnet, SSH encrypts the communication channel between you and the server, and much like a scrambled telephone line, prevents "man in the middle" line tapping of your login session, protecting your passwords and other details.

At this time, SSH is still mainly a UNIX utility. There are however, two commercial SSH clients available for the windows platform:

SecureCRT - http://www.vandyke.com

F-Secure-SSH - http://www.datafellows.com/gallery/

The official repository for unix versions of the SSH application is ftp://ftp.cs.hut.fi/pub/ssh.
SSH clients are functionally very similar to a telnet client, and once you have familiarized yourself with using telnet, SSH present little new to learn, and may form the basic of a secure retrieval of credit card information from your account. In some ways, this makes SSH a natural companion to SSL encryption, ensuring that at no time in the ordering process are your customers orders ever transmitted in plain text over the internet.