安装Add a Logon Warning Notification to Linux

Log into the Linux device
Run the following command in a terminal
# create the logon notification text
sudo nano /etc/logon-warning.txt

Enter the text to be displayed during logon, below is an example



******************************* WARNING *******************************
*                                                                     *
* This system is intended for use by authorized users only.           *
* Unauthorized or improper use of this system is strictly prohibited. *
*                                                                     *
***********************************************************************

Press CTRL+O, Enter, CTRL+X to write the changes
Continue with the following command in terminal
# edit ssh config file
sudo nano /etc/ssh/sshd_config
Press CTRL+W and search for Banner
Uncomment the Banner line by removing the #
Enter the path to the logon-warning.txt file as the value
Banner /etc/logon-warning.txt
Press CTRL+O, Enter, CTRL+X to write the changes
Continue with the following command in terminal
# restart the ssh server
sudo systemctl restart ssh*
That's it, try connecting to a new session and the logon warning message should be displayed