This is a continuation of the previous session of Overview of DNS. In this session we will install, configure and use BIND as a private network DNS server(ns1.arif.edu.pk). The three client machines are Kali Linux, Windows10 and Winxp. The main configuration file of DNS named.conf is discussed to add trusted access control list of clients and to mention about recursive or iterative DNS queries. Forward and reverse zone files are created with quite a discussion of different types of DNS resource records. Finally the client side configurations are done on both Linux and Windows machines.

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.