Table of ContentsSummaryIntroductionTraditional Packet FiltersStateful Packet FiltersApplication GatewayConclusionSummaryOne of the most important tools used to secure networks is the firewall. A firewall can be hardware or software. It filters all network traffic to prevent unauthorized access between computer networks. Other types of network security are access control, antivirus and antimalware, data loss prevention, email security, web security, and wireless security. Traditional packet filters, application gateway, and stateful packet filters are used to achieve this defense. Individually, all filters work in different ways to filter and control traffic. Some firewall requirements are that all communications pass through the firewall, that the firewall allows access to information that has been authorized, that the firewall can withstand attacks at the time of an attack, block outgoing network traffic based on source or destination IP addresses and block network traffic based on content. Currently, a few large companies like Cisco and Check Point are two of the major firewall vendors. Say no to plagiarism. Get a custom essay on “Why Violent Video Games Should Not Be Banned”?Get Original EssayIntroductionIn 2013, Yahoo was one of the leading companies to suffer a data breach in the 21st century. Businesses need firewalls. Firewall protection is for everyone. There are personal, small organization, and enterprise firewalls. What is your data worth to you? It is important for organizations to protect lost data, confidential data and staff time. The three main categories of firewalls are traditional packet filters, application gateways, and stateful packet filters. This article will discuss network security, specifically firewalls, the different types of firewalls, and the pros and cons of each packet filter. Traditional Packet Filters A traditional packet filter is the most basic filter of the three presented. It examines each datagram one by one. It decides whether to prevent data transmission or allow data transmission based on “admin-specific” rules. In other words, it ensures network security by sorting established network communication based on the information contained in the TCP/IP headers of each packet. In the network layer of the OSI model, the data used by packet filters contains the destination port and protocols, source port, destination IP address, and source IP address. A few types of protocols are TCP and UDP. Packet filters can be performed using ACLs, commonly established on most routers. One advantage is performance; Traditional packets process information only on a single layer, which improves efficiency and makes them very fast. The second advantage is that it is cost effective. Finally, traditional packet filters are useful for transferring management. However, a drawback is that packet filters do not track TCP session material created when clients communicate with each other. As Mr. Dnaiel Newman says, "When the initial communication with clients starts, it uses TCP, they perform a three-way handshake, which is used to establish the TCP session." Since these sessions are not supervised by packet filters, clients become easy targets.