Banner is something which you will see before or after you login to a particular system.
In this post I will show you how to create a banner to give a info about the machine which the user is about to access.
Check this file in your machine
# cat /etc/issue
CentOS release 6.2 (Final)
Kernel r on an m
or
# cat /etc/issue.net
CentOS release 6.2 (Final)
Kernel r on an m
This is the file which is read before you login to the machine so we will make some changes here:
# vi /etc/issue
This node contains Oracle Database 11gR2 and the owner of this node is Deepak.
This file is read after you log in successfully to your node
# vi /etc/motd
Welcome Deepak you have successfully logged in.
# vi /etc/ssh/sshd_config
# Add a line 129
Banner /etc/issue
Restart the ssh services
# service sshd restart
Stopping sshd: [ OK ]
Starting sshd: [ OK ]
Try to ssh your machine from a client machine
# ssh 10.10.10.19
This node contains Oracle Database 11gR2 and the owner of this node is Deepak.
root@10.10.10.19's password:
Last login: Sun Aug 5 15:13:05 2012 from 10.10.10.30
Welcome Deepak you have successfully logged in.