 Remote Login 

Over the internet you can log in to any computer on which
you have an account or which allows public log ins.  This
includes many database services and almost all library
catalogs.  The means of doing this is called telnet.  Tel-
net is the remote login facility of internet, and once a
connection is made, works transparently.  It's a heady ex-
perience to log into your account, telnet to Yale to check
on a book, then to Dartmouth to look up a Shakespeare ref-
erence, then to U of Michigan for a weather report, then to
Stanford for a bibliographic search--all from the comfort
and convenience of home (and at no charge).


 Magic 

Telnet makes your computer seem to be connected to a remote
computer.  What you enter from your keyboard is redirected
to the remote computer.  What the remote computer outputs
is redirected to your monitor.  It doesn't matter how far
away the other computer is.  








 How To Do It 

To telnet to another computer you simply type telnet followed
by the address of the computer to which you are connecting.
For example:

              telnet newton.dep.anl.gov

You can also use the remote computer's IP address:

              telnet 146.139.100.50

which sometimes works when a domain name will not.


 Pay Attention 

When you enter telnet with a valid address, you will see
the message:  Trying... 

When the connection is made, you will see :
              Connected to newton...
              Escape character is '^]'.

Pay close attention to this escape character message. 
Telnet is telling you which key you can press to get 
out of the current telnet session if things get hope-
lessly hung up.


 What If Something Goes Wrong 

If telnet is unable to make a connection you may see one
of the following messages:
              unknown host
              Host is unreachable

Don't be fooled.  These messages may be caused by:
    1) Misspelling the address of the computer
    2) The remote computer is temporarily down
    3) The remote computer is really not on the internet

The remedies are to a) try again carefully; b) try again
later; c) keep trying; d) give up.

 User IDs and Passwords 
 
Even though many remote computers are designed for public
access they still require a log in user ID and password.
Often, the system will tell you what to type.  In other 
cases the user ID and password are published elsewhere and
you just need to know what they are.  Finding out is
relatively easy over the net.







  Words Of Warning 

When you are finished working on a remote computer, log out
normally.  You will be returned to the telnet prompt
(telnet>) of your local host computer.  To exit the telnet
program altogether type quit (or q) from the telnet prompt.

Two words of warning:
    1) Response times from remote computers may be slow,
       especially during peak internet traffic hours.  Be
       patient.
    2) If things become hopelessly hung up when you are 
       halfway around the world, use the escape character
       that you conscientiously wrote down when you started.

 Telnet Tricks 1 

Before we start a sample telnet session, here are a couple 
of useful telnet tricks.
    1) An alternate way to start a telnet session is to
       type telnet and then press Enter.  Then type open
       with the address of the computer to which you want
       to connect.  In this way you can keep telnet going
       while you open and close different connections.
 
   2) Pressing z at the telnet prompt will suspend telnet
       and allow you to work in unix.  To exit unix and
       return to telnet type fg.  This does not work in
       all unix shells.               

 Telnet Tricks 2 

When you telnet to certain computers, a port number is
required to connect to the service you want.  For example,
to connect to the weather underground at the University 
of Michigan you must enter the following command:

     telnet downwind.sprl.umich.edu 3000

Note the space before the port address 3000.  You will find
several common services that require a port address.

Press PgDn to login and start a sample telnet session...


 Get It? 

It's always sunny in San Diego.

That's how telnet works.  Press PgDn to continue...










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