[MPICH] passwordless rsh/ssh

[Kevin C.]

Dear all

I manage to get rshd/rsh and ssh to work. I can rsh / ssh to myself 
localhost. I notice that I cannot log in as root via rsh and have to use a 
normal user account for rsh. Is this normal? Does it matter to MPICH whether 
it's root or not root passwordless login?

When I ssh/rsh to another machine I have to use it's IP address. How do I 
get around this so that I can rsh/ssh using hostname?

I manage to get ssh passwordless to localhost, but not to other hosts. If I 
was using ssh, how would I configure MPICH-1 to use ssh instead of it using 
rsh by default?

Did anyone know how to make rsh passwordless?