Limit Access from Remote Workstations

You should ensure that you have an /etc/hosts.allow file present. Populate it with the workstations you want to allow access.

vi /etc/hosts.allow
daemon_program:client_list:options

Here's an example:

#vi /etc/hosts.allow
in.telnetd:15.23.1.1,15.23.1.2:
in.ftpd:15.23.1.1,15.23.1.2:
in.rshd:15.23.1.1,15.23.1.2:
in.rlogind:15.23.1.1,15.23.1.2:
:wq! (saves and quits vi)