The aim of each lab exercise is to progressively introduce someone to debian server hardening techniques and security principles. In the final lab exercise (exercise 5), i secure the server with tools such as iptables and Fail2ban and i implement a custom DNS server with BIND to resolve the example.com to a University of Patra's IP address. To evaluate the effectiveness of the above configurations , i run a series of tests against the VM using Nmap and Python based port scanning, DoS attack python scripts and a DNS cache poisoning attempt using Python. The related web traffic is monitored and analyzed using tcpdump.