Types of Firewalls
Firewalls prevent malicious actors and cyberattacks from damaging your network. Firewall effectiveness depends on secure setup, continuous testing, and proactive management.
Gil Shwed and developer Nir Zuk pioneered graphical interfaces that made it easy to use firewall software. Their work helped create firewalls that were widely adopted in businesses and homes.
This type of firewall controls network traffic at the session layer of the OSI model. A circuit-level gateway firewall inspects the TCP handshakes between packets sent to untrusted hosts. It does not examine the contents of packets or identify individual users, but does limit the amount of information that can be transferred between hosts.
A host-based firewall is installed on a specific computer and monitors inbound and outbound network activity. These are often used to protect individual workstations from malware or to control data transfer to remote locations. Host-based firewalls may include third-party software or be included in the base operating system on a device like Windows.
Content filtering, which identifies inappropriate and dangerous content, is a common feature in most modern firewalls. It can prevent employees from accessing sites such as Facebook that are viewed as a waste of time or distract from business tasks. Firewalls can also be configured to block communication between malware infected computers that have gained unauthorized access to the network and command and control servers that are controlled by the attackers. These are referred to as botnets and can cause significant network disruption if not detected early. Firewalls can detect these by correlating firewall logs with other security data sources such as endpoint or identity systems.