PortSentry

As a system administrator, one major concern is to protect the system from network intrusions.

This is where PortSentry comes into the picture. It has the ability to detect scans on a host system and react to those scans in the way we choose.

Getting Ready

To demonstrate the implementation and usage of PortSentry, we need two systems on the same network that can ping each other.

Also, we need the Nmap package on one system, which will be used as the client, and on the other system, we will install and configure the PortSentry package.

To install the Nmap package, use the following command:

apt-get install nmap

How to do it?

1. On the first system, we install the Portsentry package, using the following command:

   apt-get install portsentry
   

   

2. During the installation process a window will open containing some information about Portsentry. Just click OK to continue:

   

3. As soon as the installation completes, portsentry starts monitoring on the TCP and UDP ports. We can verify this by checking the file...