Enhancing Network Security in Linux Environment

Designing a secured network is the most important task in any enterprise or organization development. Securing a network mainly involves applying policies and procedures to protect different network devices from unauthorized access. Servers such as web servers, file servers, mail servers, etc., are the important devices in a network. Therefore, securing these servers is the first and foremost step followed in every security implementation mechanism. To implement this, it is very important to analyse and study the security mechanisms provided by the operating system. This makes it easier for security implementation in a network. This thesis work demonstrates the tasks needed to enhance the network security in Linux environment. The various security modules existing in Linux makes it different from other operating systems. The security measures which are mainly needed to enhance the system security are documented as a baseline for practical implementation. After analysing the security measures for implementing network security, it is important to understand the role of network monitoring tools and Linux inbuilt log management in maintaining the security of a network. This is accomplished by presenting a detailed discussion on network monitoring tools and log management in Linux. In order to test the network security, a network is designed using Linux systems by configuring different servers and application firewall for packet filtering. The security measures configured on each server to enhance its security are presented as part of the implementation. The results obtained while an unauthorized user accessing the servers from the external network are also documented along with attack information retrieved by different network monitoring tools and Linux inbuilt log messages