Implementing Firewall Technologies

Implementing Firewall Technologies As networks continue to evolve over time, they are increasingly being used to transfer and store sensitive data. This intensified the need for stronger security technologies, which led to the invention of firewalls. The term firewall originally referred to fireproof walls, usually made of stone or metal that prevented the spread of fire among connected structures. In the world of networking, firewalls separate protected areas from unprotected areas. This prevents unauthorized users from accessing protected network resources. Initially, basic access control lists (ACLs), including standard, extended, numbered, and named, were the only way to provide firewall protection. Other firewall technologies began to mature in the late 1990s. Stateful firewalls use tables to track the real-time state of end-to-end sessions. Stateful firewalls consider the session-oriented nature of network traffic. Stateful firewalls first use the "Established TCP" option for ACLs. A firewall separates protected areas from unprotected areas. This prevents unauthorized users from accessing protected network resources. There are two common methods for implementing firewalls: • Packet filtering firewalls - Usually routers with the ability to filter packet content, such as Layer 3 information and sometimes Layer 4 using ACLs. • Stateful firewall - Monitors the status of a connection, whether it is in an initiation, data transfer, or termination state. Standard and extended IP ACLs can be used to provide packet filtering firewall capabilities. They are basic tools used for basic network traffic filtering and to mitigate various network attacks. Deciding which one to use depends on the type of traffic and the source and destination of the traffic. ACLs are associated with network traffic flows. Network topology determines how ACLs are created and applied.