Commands, tricks & cautions that will be used here have been tested only on a Ubuntu 12.04 VPS. Though, most of the commands should work in other Unix like system without any change.
In this lesson we will see how should a newly launched/opened server be configured for basic security & proper accessibility. Usually you get an IP address & a root password for logging in as root, as soon as you open a new cloud/vps server from rackspace/digitalocean or some others like these.
1. Connecting to the remote system through/using SSH:
SSH(Secure Shell) is a protocol used to securely loggin in to a remote system & also ssh is the tool used in Linux that connect to the remote server over the SSH protocol.
The terminal will show a message and will prompt
.... Are you sure you want to continue connecting (yes/no)?
Type yes & press enter & then in next prompt enter your root password that was provided by that server provider while opening a VPS. So, now we are logged in to the remote system as root user.
2. Change your root user’s password:
You used the root password that was generated & provided by the server provider & the first thing is to change this password. Enter the following command on the terminal.
It will first ask the current root password & after entering the current password it will ask your desired new password twice for confirmation.