Paper Title
Communication Network and Security-An Overview of Firewall and Types of Firewalls

A network is a group of two or more computer systems linked together which allows computers to exchange data. The internet is a connection of computer to any other computer anywhere in the world via dedicated routers and servers. Computer networks are involved in almost all sectors worldwide including commercial, military and government sectors where network security is major concern. With increasing technology threats are also increasing. Network security is security provided to a network from unauthorized access and risks. By assigning the user identification and password, we can provide protection up to some extent. The internet consists of computer based router. User’s Information can be obtained by unauthorized persons or firms by using special programs such as “Trojan Horses”, planted in the routers. Internet threats will continue to be a major issue as long as the information is accessible, and threats are transferrable across internet. Common internet threats are Eavesdropping, Viruses, Worms, Trojans, Phishing, IP Spoofing Attacks, Denial of Service, etc. Common defence mechanisms are Cryptographic systems, Firewall, Intrusion Detection Systems, Anti-malware software and Scanners, Security Socket Layer (SSK) etc. Among these, Firewall is an access control device that manages and regulates the network traffic based on some protocols. A firewall establishes a barrier between a trusted internal network and the internet. An overview of firewall and types of firewalls will be discussed in the paper. This paper is a collection from different sources like Firewall and Types of firewall by Sanket R Jain, , Internet Firewalls and Security A Technology Overview By Chuck Semeria and related articles from Internet.