Setup a logon banner for ssh clients to see when they login

SSH (Secure Shell) is a protocol for creating a secure connection between two computers. The secure SSH connection provides authentication and encryption. In the SSH server, it is possible to configure logon or welcome banner with the use of the Banner directive in /etc/ssh/sshd_config file.The Banner directive is only available for ssh protocol version 2 and by default there are no banner configured.

Configutration

1.       Create a banner file. (e.g. /etc/banner) using vi editor.

# vi /etc/banner

**********************************

                                ******** WELCOME TO REDHAT *******

**********************************

2. Configure the ssh configuration file  /etc/ssh/sshd_config file and add the line Banner /etc/banner  to it.

# vi /etc/ssh/sshd_config

Banner /etc/banner

3. Restart sshd daemon for the changes to take effect

# service sshd restart

Example

If we are accessing server using ssh , message will appear as follows:

[root@mail ~]# ssh 10.30.32.206

**********************************

*********WELCOME TO REDHAT********

**********************************

root@10.30.32.206's password: