When you login to your Ubuntu server with SSH you may see a message like this:

Welcome to Ubuntu 12.04.4 LTS (GNU/Linux 3.11.0-23-generic x86_64)

* Documentation:  https://help.ubuntu.com/

Last login: Tue Jun 24 21:00:01 2014 from 123.123.123.123

It's called the Message Of The Day (MOTD). It's created by running, in numerical order, the scripts in /etc/update-motd.d. On my system I have:

00-header
10-help-text
90-updates-available
91-release-upgrade
98-fsck-at-reboot
98-reboot-required
99-footer

You can of course edit those scripts or add more. How can you disable the MOTD? Firstly ensure you have this in /etc/ssh/sshd_config:

PrintMotd no

If you’re using PAM, you may still see the message, despite turning it off in sshd_config. In which case edit /etc/pam.d/sshd:

#Print the message of the day upon successful login.
#session    optional    pam_motd.so

Be sure to comment out the second line.

In my case, I don’t want connecting users to see the dynamically created MOTD, I just want a plain, old banner with a legal notice, something like this:

WARNING<strong> :</strong> Unauthorized access to this system is forbidden and will be
prosecuted by law. By accessing this system, you agree that your actions
may be monitored if unauthorized usage is suspected.

For the more creative, why not use a cool ASCII text banner?

When you’ve made your banner, save it to /etc/ssh/sshd-banner (you can specify a different directory if you like), and edit /etc/ssh/sshd_config again and add this line:

Banner /etc/ssh/sshd-banner

Be sure to then restart SSHD:

$ sudo service ssh restart