What is the default root password when using sudo on Diablo? I've tried rootme, fakeroot, and the password that I entered when installing the PC Connectivity package (ssh). I also tried to install rootsh from the Application manager. But I get "Download failed".

AFAIK, there is no root password set, so you need to either try installing rootsh again or isntall ssh.

The password I used when I installed ssh doesn't work when I use sudo with some command (e.g. vi) and am asked for a password before the command is executed.

the password you're asked fo is the currently connected user's one.
sudo gets your user password and then check in /etc/sudoer to see if you're allowed to do the action you want to do.
I don't know the user's password, it might not have one and it might not be declared in sudoer.

Try this from the xterm on your NIT:

ssh root@localhost

then use the root password you gave it when you installed ssh. This will log you in as root. From there you can use visudo to change the sudorers file to your liking.

Thank you. This is confusing because ssh asks for a root password when it is installed (by the way I just found out that that password works when executing ssh). But requires a different password when using sudo.