What is a Firewall?
A firewall is a system that provides network security by filtering incoming and outgoing network traffic based on a set of user-defined rules. In general, the purpose of a firewall is to reduce or eliminate the occurrence of unwanted network communications while allowing all legitimate communication to flow freely. In most server infrastructures, firewalls provide an essential layer of security that, combined with other measures, prevent attackers from accessing your servers in malicious ways.
How Do They Work?
It is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system.
A firewall works as a barrier, or a shield, between your computer network and internet
- Generally the firewall has two network interfaces:
- One for the external side of the network.
- One for the internal side.
- Its purpose is to control what traffic is allowed to be transfered from one side to the other.
- Firewalls blocks traffic/data/packet unintended for particular IP addresses or server ports.
It protects internal users from the external network threats.