If you want to show a Welcome message when you login into an ssh shell in gnu/linux then there are some simple steps to do that.
1. First off login to our server as root. Then type in the following:
vi /etc/motd
Now type in the security login message you wish all users to see once they login to your server through SSH.
Try something like this as a start:
2. Now press Shift+: then type x to quit and overwrite.
Logout of SSH then log back in, you will receive your new greeting!