Secure Shell (SSH)

• What is SSH?

  SSH is a program for logging onto and executing commands on a remote host. It is intended to replace telnet, rlogin, and rsh, and provide secure encrypted communications between two untrusted hosts over an insecure network. X11 connections can also be forwarded over the secure channel. The department currently uses SSH1 (not SSH2).

• How do I use SSH?

  To logon:
  ssh host.ucr.edu

  To execute a command:
  ssh host.ucr.edu command

  Where host is the name of the host you wish to access and command is the command you wish to execute.

• What is SCP?

  SCP is a program for transfering files to/from a remote host. It is intended to replace rcp and provide secure encrypted transfers between two untrusted hosts over an insecure network.

• How do I use SCP?

  To transfer a file from the current directory on localhost to the home directory on elsewhere:
  scp file login@elsewhere:

  To transfer a file from the home directory on elsewhere to the current directory on localhost:
  scp login@elsewhere:file .

• Do I have to enter a password each time?

  No. If you want to ssh/scp from account1 to account2 without having to enter the password each time, create a key in account1 using ssh-keygen ( do not enter a password when it asks for one, simply hit enter, twice). Place a copy of the content of the newly generated   ~/.ssh/identity.pub   in account1 into the file on account2  ~/.ssh/authorized_keys . You should now be able to ssh/scp from account1 to account2 without having to enter your password each time.

• But I'm using MS Windows/Apple Macintosh, can I still take advantage of these tools?

  Yes. SSH/SCP are available for these operating systems. Putty is the recommended implementation for Win32 platforms. The latest version also supports SSH2. After you download the file, you must configure it to connect to the department. A graphical alternative to scp is winscp
  NiftySSH is the recommended implementation for Macintosh platforms.