What it is

A firewall is a system that filters network traffic on the basis of specified rules. Firewalls can be hardware, software, or a combination of the two.

Problem it addresses

By default, a network will allow anyone to enter and depart as long as they follow the network’s routing rules. Because of this default behavior, securing a network is challenging. For example, in a microservices-based banking app, the services communicate with one another by transmitting highly sensitive financial data through their network. A malicious actor may infiltrate the network, intercept communication, and do damage if there was no firewall in place.

How it helps

A firewall examines network traffic using pre-defined rules. All traffic is filtered, and any traffic coming from untrustworthy or suspect sources is blocked — only traffic configured to be accepted gets in. Firewalls establish a barrier between secured and controlled internal trusted networks.

Last modified August 15, 2022: Link microservices (#1199) (edda257)