You can also use [ssh][3] to configure password-less login to a remote computer.

It is just (on computer a):

 $ ssh-keygen # use an empty password!
 $ scp ~/.ssh/id_rsa.pub computer_b:.ssh/authorized_keys

That's it.

Now you can do a

 $ ssh computer_b

without having to enter a password.

You can optionally configure things like:

- host alias for computer_b, e.g. to be able to enter `ssh alias`
- set public-key authentication as default for that host/alias
- allow only public-key authentication (for the sshd on computer_b)

Unless you can't use ssh, it seems to be much more convenient to setup than rlogin.

Plus, ssh protects you against [main-in-the-middle attacks][2] and [eavesdropping][1].

## Troubleshooting

Make sure that the `~/.ssh` has the right permissions (on both systems) - i.e. is only accessible by your user - otherwise ssh ignores it. That means only `rwx------` for the directory and `rw-------` for the files. Use `ls -l` and `ls -ld` to verify this.

Make sure that the remote `~/.ssh/authorized_keys` contains the correct public key. Verify via:

 $ ssh computer_b cat '~/.ssh/authorized_keys' # remote
 $ cat ~/.ssh/id_rsa.pub # local

If the setup does not work like this, perhaps you have to explicitly configure the client side, i.e. adding something like this to `.ssh/config`:

 Host computer_b
 Hostname some_hostname
 User juser
 PreferredAuthentications publickey # makes testing easier
 IdentitiesOnly yes
 IdentityFile ~/.ssh/id_rsa.pub

For diagnosing issues it is also useful to add `-v` to `ssh` call, e.g.:

 $ ssh -v computer_b


[1]: http://en.wikipedia.org/wiki/Eavesdropping
[2]: http://en.wikipedia.org/wiki/Man-in-the-middle_attack
[3]: http://en.wikipedia.org/wiki/Secure_Shell