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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:
\S
Kernel \r on an \m
On an Ubuntu machine, the banner would look something like this:
![](https://epubservercos.yuewen.com/EB7950/19470399001594806/epubprivate/OEBPS/Images/Chapter_23.jpg?sign=1739642965-FUESo3WqmCbkgXI4siKPSD6gGcecIDgc-0-3a381253474e3b78c9e364e1a2a824fe)
On a CentOS machine, it would look something like this:
![](https://epubservercos.yuewen.com/EB7950/19470399001594806/epubprivate/OEBPS/Images/Chapter_60.jpg?sign=1739642965-LnNE7wzR8VQ4d4ydQDNl95kF1iH9dFIg-0-ba93ae8c00b8bc34facb875d27c54f45)
You could put a security message in the issue file, and it would show up after a reboot:
![](https://epubservercos.yuewen.com/EB7950/19470399001594806/epubprivate/OEBPS/Images/Chapter_48.jpg?sign=1739642965-tBBoAZ9CqVtrScufKJIkBfyllOyv0lvG-0-af3af3153bc01f814403be18c2fac65f)
In reality, is there really any point in placing a security message in the issue file? If your servers are properly locked away in a server room with controlled access, then probably not.