There are several options available for firewalls
Source: wallpaperflare.com
When implementing a strategy for firewalls at a company, there are four options available that can examine traffic for malicious code.
Packet-Filtering Firewalls
Packet-Filtering Firewall examines the header information of data packets that come into a network. The firewall determines whether to deny a packet or allow it to transfer to the next network connection, depending on the rules programmed into the firewall. Packet-filtering firewalls examine incoming packet headers and can filter packets based on header information like destination address, source address, packet type, and other information. Packet-filtering firewalls’ approach to transferring data using a direct accept or deny function has the capability of securing an entire network without the need for applying additional devices. It is one of the most commonly used firewalls for today’s businesses.
Application Layer Proxy Firewalls
Application Layer Proxy Firewalls are frequently installed on a dedicated computer separate from the filtering router, but it is often used in conjunction with a filtering router. The application firewall is also known as a proxy server due to its ability to be configured to run special software that acts as a proxy for a service request. The benefit of a proxy server involves the ability to apply one within a demilitarized zone and divert potential threat agents to it rather than on a web server. The disadvantage of using a proxy server concerns its frequent design for only one or a few protocols and cannot be easily configured to execute other protocols. Even though it has drawbacks, the application layer proxy firewalls remain an effective method of transferring information throughout computer networks while minimizing risk to the web server.
Media Access Control Layer Firewalls
Media Access Control Layer Firewalls make filtering decisions based on the specific host computer’s identity, as represented by its media access control or network interface card address. The media access control layer firewalls link the addresses of specific host computers to ACL entries that identify the specific types of packets that can be sent to each host, and block all other traffic. This is one of the lesser used firewalls in comparison to the application layer proxy firewalls and packet-filtering firewalls.
Hybrid firewalls
Hybrid firewalls combine the elements of the packet-filtering, application layer proxy, and media access control layer firewalls. The hybrid firewall system may consist of two separate firewall devices, each connected so that they work in tandem. The advantage of the hybrid firewall involves the ability of information security professionals to make security improvements without replacing existing firewalls. The hybrid firewalls’ generation are in common use today due to companies seeking to provide added security to existing networks. Hybrid firewalls exist in two forms-the United Threat Management firewall and Next Generation firewall. Each type has gained popularity among companies due to their ability to combine traditional firewall functions with other network security functions, such as deep packet inspection, IDPs, and the ability to decrypt encrypted traffic. It has become a common solution due to giving security staff the ability to implement the features of all firewall types while satisfying an “all-in-one” strategy that may be more cost effective than having independent devices for implementing firewalls for specific business needs.