Firewalls can be physical hardware situated between the gateway and network. Firewalls can also take the form of software that is placed at an endpoint, such as a computer or mobile device. Cloud-based firewalls, also known as firewall-as-a-service (FaaS), function much like other internet-based SaaS solutions, monitoring packets in the cloud.
The most common firewall functionality includes:
Next-generation firewalls – In response to an everchanging threat landscape, next-generation firewalls extend traditional firewall features, adding security functions, such as intrusion prevention, anti-malware, VPN, and encrypted traffic inspection. These firewalls offer significant application control and visibility.
Packet-filtering firewalls – These firewalls execute a basic examination of all data packets arriving from the network router and look at the source and destination IP address, port number, protocol, and other surface-level data.
Proxy firewalls – Also known as an application-level firewall, this type of firewall filters network traffic at the application layer. Such firewalls are most often used in the cloud or with another proxy device.
Web application firewalls – These firewalls filter, monitor, and block data packets traversing websites or web applications. They are often used in the form of a server plugin, cloud service, or network appliance.
Network address translation firewalls – These firewalls assign a public address to a group of devices inside a private network. Because individual IP addresses are not visible, attackers searching for IP addresses on a network are unable to capture this sensitive information.