This document discusses the process of securing a system using IP Table firewall. It covers topics such as denial of SSH access, access of SSH service, ping service denial, ports 80 denial, IP address access control, and port 80 one-way traffic. It also explores the advantages and disadvantages of firewalls with iptables and provides suggestions for overcoming the disadvantages. Additionally, it discusses the role and significance of circuit relay firewall in securing communication. The document includes a bibliography for further reading.