CS Dept SSH Frequently Asked Questions

  1. I followed the directions and it didn't work. What should I do?

    Check the following:

    • Is your ~/.ssh/authorized_keys file writable only by your user (i.e. 644 permissions)? If your ~/.ssh directory writable only by your user (i.e. 755 permissions)? Note that group writability on these files is not permitted by ssh.

    • Did you cut & paste the public entry when you copied it into ~/.ssh/authorized_keys? Each entry in that file must be on a single line. Delete any extra newlines and try again.

    • If your remote machine is a unix or linux machine:

      • The private key must be in a file named id_rsa, or else you must tell ssh where it is (using the -i option). Note that this file must be readable only by your user (i.e. 600 permissions).

  2. Can I use ssh1 to connect to the department?

    No, ssh1 has been disabled. Please use ssh2.

  3. Can I use ssh2 to connect to the department?

    Yes, in fact ssh1 is no longer supported.

  4. How do I transfer files to/from the department using ssh?

    Use scp. Rsync and cvs also know how to use an ssh connection to transfer files. There are probably other choices, too.

  5. What machine(s) should/can I connect to?

    The only machine you can connect to from outside the department is ssh.cs.brown.edu. This machine is a dedicated portal to reach into the department via ssh.

  6. How can I ssh between machines?

    Just as you need a ssh key to ssh from outside the department through ssh.cs.brown.edu to your machine of choice, you must also authenticate yourself when sshing between departmental machines. One way to authenticate yourself is with a Kerberos ticket. You obtain Kerberos tickets by logging in to any Linux machine, unlocking a screensaver, or running the kinit command; once you have a Kerberos ticket, you can ssh between departmental machines without entering passwords. Kerberos tickets expire after 8 hours.