rhosts - allow rlogin, rsh and rcp connections to the local machine
without a password.
The .rhosts file can allow specific remote users and/or hosts to execute
commands on the local machine. The file uses the following format:
host [user | @group]
Such an entry grants password-free access for the user with the login
name user from host. If no user is specified, the user must have the
same login name on the remote host and the local host. For security
reasons you should always use the FQDN of the hostname and not the short
hostname. Netgroups can be specified by preceeding the group by an @
The .rhosts file must be owned by the user or root, and writable only by
rsh(1), rlogin(1), rcp(1).