Mastering Linux Security and Hardening

Using the issue file

The issue file, also found in the /etc directory, shows a message on the local terminal, just above the login prompt. A default issue file would just contain macro code that would show information about the machine. Look at the following example:

Ubuntu 16.04.3 LTS \n \l

Or, on a CentOS machine:

\SKernel \r on an \m

On an Ubuntu machine, the banner would look something like this:

On a CentOS machine, it would look something like this:

You could put a security message in the issue file, and it would show up after a reboot: ...