Columbia University in the City of New York
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Telnet and SSH

SSH on CS Computers

SSH Key Fingerprints

The first time you connect to a computer using ssh or similar, it will display a key fingerprint which you should verify is correct. This is to prevent what’s called a man in the middle attack where an attacker pretends to be the machine you’re connecting to and intercepts your password or traffic. Our fingerprints are:

clic

RSA key fingerprints: 
MD5:b7:21:b5:c7:3d:3d:ee:39:9e:3a:84:62:62:f0:c5:00
SHA256:fXXbsrEV0Clt25+NkwhB6bLnG2DirhJIC4guhaGJO7k

ECDSA key fingerprints: 
MD5:d4:dd:4b:22:7a:67:a1:9c:a7:a2:df:a7:bb:d4:13:1d
SHA256:O7ynd4TcmR3m4R9oF/wAMqDmEdnpE7/E0VYg08IgrTA

compute

RSA key fingerprints: 
MD5:31:78:59:e8:94:47:46:f6:db:07:90:0f:17:30:76:5b
SHA256:DxnitFKP67+8pSNreNh28AeEaUfyULLI9BbnTTNJhcU

ECDSA key fingerprints: 
MD5:5d:18:35:1d:1b:01:73:47:f5:69:e4:f9:24:d8:b2:2b 
SHA256:mLTAjJwwpiFzL14RyWY0yP4xlRIr7HvLmvUXVWJ2LXg

Connecting to CS Computers

For security reasons, we have turned off all commands that use clear text passwords such as telnet (use ssh instead), ftp (use sftp instead), and rsh (use ssh instead).

Via a windows ssh client

Obtaining Putty

To download Putty, please visit: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

  1. Click putty.exe and download it to your desktop
  2. Double-click on the putty.exe icon on the desktop to start putty
  3. In Host Name section, type in: “clic.cs.columbia.edu” or “compute.cs.columbia.edu”
  4. Under Protocol, be sure to check “SSH”
  5. Under Saved Sessions, type in “Cluster” and click Save. (From now on, you should be able to double-click on the saved session to connect to clic.cs.columbia.edu or compute.cs.columbia.edu.)
  6. Click Open
  7. For the first time you log into clic or compute using putty, you will see a new window pop-up with “Putty Security Alert: The server’s host key is not cached in the registry. You have to guarantee that the server is the computer you think it is. The server’s key fingerprint is: … .. .. “. Click “Yes”
  8. You should see “login as: ” in the main window. Type in your username.
  9. Type in your password and you should be logged into clic or computer