System Administration Guide
Chapter 7, Connecting to other computers with UUCP

Preventing unknown sites from logging in

Preventing unknown sites from logging in

The script remote.unknown is executed when a site whose name does not appear in your Systems file dials into your system. It logs the conversation attempt and fails to make a connection. If you wish to allow such ``unknown'' systems to log in to your system, you can change the permissions of this file so it cannot execute and your system accepts any communication requests. To do so, enter the following commands while logged in as root:

cd /usr/lib/uucp
chmod 000 remote.unknown