A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules. Firewalls have been a first line of defense in network security for over 25 years. They establish a barrier between secured and controlled internal networks that can be trusted and untrusted outside networks, such as the Internet. Firewalls can be hardware, software, software-as-a-service (SaaS), public cloud, or private cloud (virtual) .
Firewalls can be categorized as network-based or host-based systems). Network-based firewalls are positioned between two or more networks, typically between the local area network (LAN) and wide area network (WAN), and their basic function is to control the flow of data between connected networks). They are either a software appliance running on general-purpose hardware, a hardware appliance running on special-purpose hardware, or a virtual appliance running on a virtual host controlled by a hypervisor). Firewall appliances may also offer non-firewall functionality, such as DHCP or VPN services). Host-based firewalls are deployed directly on the host itself to control network traffic or other computing resources).
Firewalls are necessary parts of any security architecture and take the guesswork out of host-level protections and entrust them to your network security device. They focus on blocking malware and application-layer attacks, along with an integrated intrusion prevention system (IPS) . By leveraging a firewall for your security infrastructure, you’re setting up your network with specific policies to allow or block incoming and outgoing traffic. Firewalls play an important role in preventing cyber attacks, protecting sensitive data, and maintaining the privacy and security of computer systems and networks.
