Basic Putty SSH HowTo
Table of Contents
- Prerequisites: What You Need to
- Download and Install Putty
- Set Up a Session
- What Now?
SSH is a protocol similar to Telnet in that it allows you to
login to a computer from anywhere on the internet. When you
login, you get a command prompt from which you can issue the
same commands that you would issue if you were actually sitting
at the remote computer's physical console.
SSH is different from Telnet because SSH uses strong
encryption for privacy and authentication. It is only secure if
your password is not guessable.
This is HowTo covers the use of Putty SSH, a particular
client program that is well suited to a Windows
Prerequisites: What You Need to Have
Before you begin, you should have a username for your
account on the system you want to login to, the DNS hostname of
that system, the SSH server key fingerprint, and your password
for that system.
In the directions below, the sample values are:
|Server Key Fingerprint:
You must replace the sample values with your own in the
This HowTo also assumes that you have a Windows box and an
internet connection that you know how to use.
Download and Install Putty
Installation is really quite trivial. Just download it from
and save it on your desktop (or somewhere else
If Putty SSH is no longer available at the link above, try
searching for "putty" from Google.
If you have trouble running it once downloaded, be sure you
are downloading it in binary format, not in ascii format.
Set Up a Session
Follow these step-by-step instructions to configure a
session in putty. A session in putty is sort of like a bookmark
- Start Putty by double clicking it.
- The GUI should initially show the Session panel. If not,
click "Session" under "Category" to display the Session
- For "Host Name (or IP address)" enter the hostname of the
computer to which you want to connect,
- For "Protocol", choose SSH, not Telnet or one of the
- Under "Saved Sessions" enter "ssh to
mmc34a.resnet.cornell.edu", but don't bother clicking the
"Save" button yet.
- Under "Category" click "Connection" to show the
- For "Auto-login username" enter your username, "wai", for
the computer you want to connect to.
- Click the "Connection"->"SSH" under "Category" to show
the SSH panel.
- For "Preferred SSH protocol version" choose 2, not 1.
SSH2 is a more modern, more secure version of the SSH
- Click "Session" under "Category" to get back to the
- Click the "Save" button to save your settings for this
session. You should now be able to quit by clicking Cancel,
restart putty, and still find the session called "ssh to
mmc34a.resnet.cornell.edu" under "Saved Sessions".
- Double click "ssh to mmc34a.resnet.cornell.edu" to open a
session to mmc34a.resnet.cornell.edu.
- If this is your first time connecting to
mmc34a.resnet.cornell.edu, you will be given a security alert
asking whether you recognize its key. This is basically
asking you to verify that the key of the host you are logging
in to is the correct key. The host's key is proof to you that
you are contacting the correct computer, not a rogue server
that is impersonating mmc34a.resnet.cornell.edu to steal your
password. Check that the key is correct. If it is correct,
click "Yes" to continue. Otherwise, click "Cancel" to abandon
the session, and alert your system administrator to the fact
that the host is being impersonated.
- When prompted, enter your password for this account.
You should now get a command prompt on the system you were
trying to contact. From here you can run programs, etc.
You have now logged into the remote computer or server.
If you are logging in to a Linux system and are new to
Linux, you may wish to check out an introductory Linux tutorial.