Which one of the following is true about firewalls?
A
It filters network traffic
B
It can be either a hardware or software device
C
It follows a set of rules
D
All of these
Correct Answer: All of these
Firewalls are filters network traffic which follows a set of rules and can either be used as hardware or software device. They are often categorized as network or host - based firewalls. Network firewall filter traffic between two or more networks while host networks run on host computers. Firewall is a network security system designed to prevent unauthorized access to or from private network. Network firewalls are used to prevent unauthorized internet users from accessing the private network especially intranets.