We recommend you use “ssh” (which stands for “secure shell”) to establish a login session with the CIS Unix systems. Under ssh, all data, including passwords, that passes over the network using the ssh protocol is encrypted, which negates the threat of a third party spying on the network traffic and reading your sensitive information.

If you are using a computer with a Unix-like operating system (including Mac OS X and Linux), you can use the slogin command in a terminal window. You typically specify both the machine name and (as an option) the username on the command line. For example, use any of:

% slogin -l joe euler.unh.edu
% slogin -l joe zeno.unh.edu
% slogin -l joe gauss.unh.edu

If you have the same username on both systems, you can omit the option:

% slogin euler.unh.edu
% slogin zeno.unh.edu
% slogin gauss.unh.edu

	The ssh protocol zealously insures that you're connecting to the precise host you specify; it uses a verification procedure involving each system's unique “host key”. So we recommend that you avoid the cisunix.unh.edu hostname when using ssh; otherwise you may see confusing messages about conflicting host keys.

Since the username is specified, slogin will skip past the login: prompt to the Password: prompt. Continue with Section 7.3, “At the Password Prompt”

A good free PC client that allows ssh connections is PuTTY; instructions for retrieving and downloading are at http://www.chiark.greenend.org.uk/~sgtatham/putty/.

PC and Macintosh ssh client software will typically request both your username and password and log you in. Proceed to the last paragraph of Section 7.3, “At the Password Prompt”.

Although the use of ssh client software is strongly recommended for establishing login sessions with the CIS Unix systems, we still allow access via (so-called) “telnet” clients as well.

If you are using a Unix-like system (including Mac OS X and Linux) with network access, the terminal-window command

% telnet cisunix.unh.edu

will connect you to a CIS Unix login server, displaying its login message and a login: prompt. A similar command will allow you to contact any specific machine; simply use the name of the machine you want (euler, zeno, or gauss) instead of cisunix in the command you type.

Some version of telnet “client” software will probably be available on any system that has a network connection. (Since we don't recommend use of the telnet protocol, we don't recommend any particular telnet client software, however.)

Similarly, details on how to use telnet client programs are beyond the scope of this document. You'll need to (somehow) tell the software to talk to one of the Unix login servers; consult the software documentation for directions.

Proceed to Section 7.2, “At the Login Prompt”.

The default login interface for new users is a simple “menu” as shown in Figure 1, “CIS Unix Menu”

Figure 1. CIS Unix Menu

This menu interface allows one-digit selection of some of the most commonly used programs on the system: the alpine program for e-mail, and the lynx Internet browsing program. You can also access the normal command shell prompt, change your password, and log out. You're told whether you have mail in your INBOX, and information about your disk quota, and (as if you need reminding) what your e-mail address is.

If you want to switch to the shell interface temporarily, choice 3 will do it for you. To make your default interface the shell instead of the menu, type 7; this will take effect at your next login.

An alternate method to use the CIS Unix systems is by typing commands to the Unix shell. Many examples in this document and elsewhere assume that you can type commands to the Unix shell. When using the shell, you have full access to hundreds of Unix commands, instead of the few shown at the menu. So you might find it's worth knowing.

The normal Unix shell prompt is a percent sign:

% 

You can type Unix commands at this prompt, for example, to run the alpine program to read and compose mail:

% alpine

When one program ends, the shell prompt reappears, and you give your next command. And so on. When you're done, type the logout command:

% logout

If you want to use the menu interface temporarily, give the menu shell command:

% menu

To make the menu interface the default when you log in, the command is menuon:

% menuon