PPPL Unix Cluster

rsh and rlogin Logging into another computer

3.1.3: slogin and ssh

ssh(1) and slogin(1) are "secure" replacements for rsh(1) and rlogin(1). You may wish to use them because:

• They provide a convenient method for accessing the Unix Cluster from off-site, since (a) rsh access to the Unix Cluster is restricted to a few domains, and (b) ssh optionally offers compression which offers improved throughput on low bandwidth connections.
• Finally, ssh knows how to forward AFS tokens to remote machines, so you may wish to use ssh within the Unix Cluster.

The primary documentation is via the manpages: ssh(1), sshd(8), slogin(1), scp(1), ssh-keygen(1), ssh-agent(1), ssh-add(1).

The main ssh web site is http://www.ssh.fi/sshprotocols2/. (Note that the Unix Cluster is currently running version 1.2.x of ssh.)

A nice tutorial on ssh is at http://www.tac.nyc.ny.us/~kim/ssh/. This includes pointers to more information.

There is also https://w3.pppl.gov/~karney/ssh-sem.txt with PPPL specific information.

There are three primarly ways in which a connection to a remote host can be authorized by ssh.

1. by prompting for a password for the remote host
2. by an rsh-style file named `~/.rhosts' (or `~/.shosts') on the remote host. See rhosts(4)
3. by the use of private and public keys, so-called RSA authentication

The first two should be easy to use. The third requires some a little more work to set up, but is more secure and does not require that the host you're connecting from be already known to the remote host.

rsh and rlogin

Logging into another computer