This session will deal with proxy server, which is a program running on a computer that sits between a client computer and the Internet and provide indirect services to client. The different uses of a proxy server for network administrator as well as for hackers are discussed. The concept of using proxy servers for hiding foot prints of a cyber attack are discussed. Finally squid proxy server is installed and configured on Ubuntu Server machine and its different uses are shown on Kali Linux and Windows10 client machines.

This session deals with how to secure your systems using a firewall, which is a network security system either h/w or s/w based, that uses rules to control incoming and outgoing NW traffic. The types of iptables (filter, nat, mangle, raw, and security) are discussed. The filter-iptables are discussed in length with input, output and forward chains and how to write rules for these chains. The practical implications of different rules are shown by running different applications. Finally the working of uncomplicated firewall (UFW) is also shown.