Q20. How does a firewall work?
Ans. This is among the popularly asked networking interview questions. The firewall ‘listens’ for what information packets are trying to leave or enter the computer system. Blocking can be done based on various criteria, such as the IP to which they are destined, the type of port used to send them, or the application of origin. One of the most complex aspects of using firewalls lies in their configuration, in deciding what types of connections are blocked and which ones are not.
