Each remote machine may have a file named /etc/hosts.equiv containing a list of trusted hostnames with which it shares usernames. Users with the same username on both the local and remote machine may run rsh from the machines listed in the remote machine's /etc/hosts file. Individual users may set up a similar private equivalence list with the file .rhosts in their home directories. Each line in this file contains two names: a hostname and a username separated by a space.
The entry permits the user named username who is logged into hostname to use rsh to access the remote machine as the remote user. If the name of the local host is not found in the /etc/hosts.equiv file on the remote machine, and the local username and hostname are not found in the remote user's .rhosts file, then the access is denied.
documented on: 02-05-99